Fixes #11002

Adopts [`go-changelog`](https://github.com/hashicorp/go-changelog) for managing Nomad's changelog. `go-changelog` is becoming the HashiCorp defacto standard tool for managing changelog, e.g. [Consul](https://github.com/hashicorp/consul/pull/8387), [Vault](https://github.com/hashicorp/vault/pull/10363), [Waypoint](https://github.com/hashicorp/waypoint/pull/1179). [Consul](https://github.com/hashicorp/consul/pull/8387) seems to be the first product to adopt it, and its PR has the most context - though I've updated `.changelog/README.md` with the relevant info here.

## Changes to developers workflow

When opening PRs, developers should add a changelog entry in `.changelog/<PR#>.txt`. Check [`.changelog/README.md`](https://github.com/hashicorp/nomad/blob/docs-adopt-gochangelog/.changelog/README.md#developer-guide). 

For the WIP release, entries can be amended even after the PR merged, and new files may be added post-hoc (e.g. during transition period, missed accidentally, community PRs, etc).

### Transitioning

Pending PRs can start including the changelog entry files immediately.

For 1.1.3/1.0.9 cycle, the release coordinator should create the entries for any PR that gets merged without a changelog entry file. They should also move any 1.1.3 entry in CHANGELOG.md to a changelog entry file, as this PR done for GH-10818.

## Changes to release process

Before cutting a release, release coordinator should update the changelog by inserting the output of `make changelog` to CHANGELOG.md with appropriate headers. See [`.changelog/README.md`](https://github.com/hashicorp/nomad/blob/docs-adopt-gochangelog/.changelog/README.md#how-to-generate-changelog-entries-for-release) for more details.


## Details

go-changelog is a basic templating engine for maintaining changelog in HashiCorp environment.

It expects the changelog entries as files indexed by their PR number. The CLI generates the changelog section for a release by comparing two git references (e.g. `HEAD` and the latest release, e.g. `v1.1.2`), and still requires manual process for updating CHANGELOG.md and final formatting.

The approach has many nice advantages:
* Avoids changelog related merge conflicts: Each PR touches different file!
* Copes with amendments and post-PR updates: Just add or update a changelog entry file using the original PR numbers.
* Addresses the release backporting scenario: Cherry-picking PRs will cherry-pick the relevant changelog entry automatically!
* Only relies on data available through `git` - no reliance on GitHub metadata or require GitHub credentials

The approach has few downsides though:
* CHANGELOG.md going stale during development and must be updated manually before cutting the release
  * Repository watchers can no longer glance at the CHANGELOG.md to see upcoming changes
  * We can periodically update the file, but `go-changelog` tool does not aid with that
* `go-changelog` tool does not offer good error reporting. If an entry is has an invalid tag (e.g. uses `release-note:bugfix` instead of `release-note:bug`), the entry will be dropped silently
  * We should update go-changelog to warn against unexpected entry tags
  * TODO: Meanwhile, PR reviewers and release coordinators should watch out

## Potential follow ups

We should follow up with CI checks to ensure PR changes include a warning. I've opted not to include that now. We still make many non-changelog-worth PRs for website/docs, for large features that get merged in multiple small PRs. I did not want to include a check that fails often.

Also, we should follow up to have `go-changelog` emit better warnings on unexpected tag.

The `docker` driver's `port_map` field was deprecated in 0.12 and this is
documented in the task driver's docs, but we never explicitly flagged it for
backwards compatibility.

This PR makes it so that Nomad will automatically set the CONSUL_TLS_SERVER_NAME
environment variable for Connect native tasks running in bridge networking mode
where Consul has TLS enabled. Because of the use of a unix domain socket for
communicating with Consul when in bridge networking mode, the server name is
a file name instead of something compatible with the mTLS certificate Consul
will authenticate against. "localhost" is by default a compatible name, so Nomad
will set the environment variable to that.

Fixes #10804

When the `-verbose` flag is passed to the `nomad volume status` command, we
hit a code path where the rows of text to be formatted were not initialized
correctly, resulting in a panic in the CLI.

* Add remaining pprof profiles to debug dump
* Refactor pprof profile capture
* Add WaitForFilesUntil and WaitForResultUntil utility functions
* Add CHANGELOG entry

This PR adds validation during job submission that Connect proxy upstreams
within a task group are using different listener addresses. Otherwise, a
duplicate envoy listener will be created and not be able to bind.

Closes #7833

When `network.mode = "bridge"`, we create a pause container in Docker with no
networking so that we have a process to hold the network namespace we create
in Nomad. The default `/etc/hosts` file of that pause container is then used
for all the Docker tasks that share that network namespace. Some applications
rely on this file being populated.

This changeset generates a `/etc/hosts` file and bind-mounts it to the
container when Nomad owns the network, so that the container's hostname has an
IP in the file as expected. The hosts file will include the entries added by
the Docker driver's `extra_hosts` field.

In this changeset, only the Docker task driver will take advantage of this
option, as the `exec`/`java` drivers currently copy the host's `/etc/hosts`
file and this can't be changed without breaking backwards compatibility. But
the fields are available in the task driver protobuf for community task
drivers to use if they'd like.

This PR fixes some job submission plumbing to make sure the Consul Check parameters
- failure_before_critical
- success_before_passing

work with group-level services. They already work with task-level services.

The `QuotaIterator` is used as the source of nodes passed into feasibility
checking for constraints. Every node that passes the quota check counts the
allocation resources agains the quota, and as a result we count nodes which
will be later filtered out by constraints. Therefore for jobs with
constraints, nodes that are feasibility checked but fail have been counted
against quotas. This failure mode is order dependent; if all the unfiltered
nodes happen to be quota checked first, everything works as expected.

This changeset moves the `QuotaIterator` to happen last among all feasibility
checkers (but before ranking). The `QuotaIterator` will never receive filtered
nodes so it will calculate quotas correctly.

Updates the deployment status and job run docs

1.16.5 contains some security fixes for zip that are notable to get: https://github.com/golang/go/issues?q=milestone%3AGo1.16.5+label%3ACherryPickApproved 

minor refactor and changelog

Closes #10646

This PR changes Nomad's wrapper around the Consul NamespaceAPI so that
it will detect if the Consul Namespaces feature is enabled before making
a request to the Namespaces API. Namespaces are not enabled in Consul OSS,
and require a suitable license to be used with Consul ENT.

Previously Nomad would check for a 404 status code when makeing a request
to the Namespaces API to "detect" if Consul OSS was being used. This does
not work for Consul ENT with Namespaces disabled, which returns a 500.

Now we avoid requesting the namespace API altogether if Consul is detected
to be the OSS sku, or if the Namespaces feature is not licensed. Since
Consul can be upgraded from OSS to ENT, or a new license applied, we cache
the value for 1 minute, refreshing on demand if expired.

Fixes https://github.com/hashicorp/nomad-enterprise/issues/575

Note that the ticket originally describes using attributes from https://github.com/hashicorp/nomad/issues/10688.
This turns out not to be possible due to a chicken-egg situation between
bootstrapping the agent and setting up the consul client. Also fun: the
Consul fingerprinter creates its own Consul client, because there is no
[currently] no way to pass the agent's client through the fingerprint factory.

Co-authored-by: Tim Gross <tgross@hashicorp.com>

When `nomad volume create` was introduced in Nomad 1.1.0, we changed the
volume spec to take a list of capabilities rather than a single capability, to
meet the requirements of the CSI spec. When a volume is registered via `nomad
volume register`, we should be using the same fields to validate the volume
with the controller plugin.

This PR adds two additional constraints on Connect sidecar and gateway tasks,
making sure Nomad schedules them only onto nodes where Connect is actually
enabled on the Consul agent.

Consul requires `connect.enabled = true` and `ports.grpc = <number>` to be
explicitly set on agent configuration before Connect APIs will work. Until
now, Nomad would only validate a minimum version of Consul, which would cause
confusion for users who try to run Connect tasks on nodes where Consul is not
yet sufficiently configured. These contstraints prevent job scheduling on nodes
where Connect is not actually use-able.

Closes #10700