This PR enables jobs configured with a custom sidecar_task to make
use of the `service.expose` feature for creating checks on services
in the service mesh. Before we would check that sidecar_task had not
been set (indicating that something other than envoy may be in use,
which would not support envoy's expose feature). However Consul has
not added support for anything other than envoy and probably never
will, so having the restriction in place seems like an unnecessary
hindrance. If Consul ever does support something other than Envoy,
they will likely find a way to provide the expose feature anyway.

Fixes #9854

ar: isolate network actions performed by client

This changes the license-fetching endpoint to respond with 204 in
OSS instead of 501. It closes #9827.

drivers/exec+java: Add configuration to restore previous PID/IPC namespace behavior

Co-authored-by: Chris Baker <1675087+cgbaker@users.noreply.github.com>

Co-authored-by: Chris Baker <1675087+cgbaker@users.noreply.github.com>

Co-authored-by: Chris Baker <1675087+cgbaker@users.noreply.github.com>

Co-authored-by: Chris Baker <1675087+cgbaker@users.noreply.github.com>

Co-authored-by: Chris Baker <1675087+cgbaker@users.noreply.github.com>

Co-authored-by: Chris Baker <1675087+cgbaker@users.noreply.github.com>

This PR adds default_pid_mode and default_ipc_mode options to the exec and java
task drivers. By default these will default to "private" mode, enabling PID and
IPC isolation for tasks. Setting them to "host" mode disables isolation. Doing
so is not recommended, but may be necessary to support legacy job configurations.

Closes #9969

The details of host volume and CSI volume requests do not show up in `nomad
plan` outputs, although the updates are detected by the scheduler and result
in an update as expected.

This closes #9966. It was looking at the query parameters
for the namespace and region, but allocation (and task!)
routes don’t have a namespace query parameter. Since the URL
generator requires the job for all calls, it makes sense to
extract the namespace and region from the job instead.

add prefix-search and auto-completion for `scaling policy info` command

- aws secret key is named incorrectly in the target docs.
  It needs to match what is in the nomad-autoscaler repo
  (see link below), otherwise the autoscaler will default to AWS sdk
  behavior, which could end up using an IAM instance profile
  or other environment variables instead of what is passed into the
  autoscaler config file.

Ref: https://github.com/hashicorp/nomad-autoscaler/blob/e60fb5268d2107ab18e2be11e5d438fedc3eb2a8/plugins/builtin/target/aws-asg/plugin/plugin.go#L27

drivers/docker: support mapping multiple host ports to the same container port

This changes the Babel compilation targets to exclude IE 11,
which results in significant payload size savings.

UI: Cross region server monitor

e2e packer build: upgrade jdk to java 14

scheduler: add tests and fix for detected host_network and to port field changes

This includes seemingly-unrelated changes because of dependency updates.