To generate oidc callback URLs our logic for handling http was not
complete, it only considered situations where the host url is localhost
and not the condition where somebody might have his/her headlamp app
running behind a http protocol.

Dockerfile: Fix alpine version typo, and separate front and back building

So that if a src/ change is made it doesn't do an npm install again.

So that if a backend part is changed, then the frontend image is
not rebuilt and vice versa.

Fix plugin reinitialization

Upgrade Nodejs 16 versions, and Alpine linux 3.15.0

headlamp-plugin: Bump version to 0.4.0

Mainly for the new nodejs 16 LTS, but also pg 14, and linux LTS.

Because Nodejs 16 is now LTS node, and it has various improvements
including better support for javascript modules.

frontend: Make workload details go back to the correct list view

Fix UI warnings

frontend: Fix warning color's contrast on dark theme

frontend: Check for a pod's conditions before using them

Those were disableBackdropClick and disableEscapeKeyDown.

This prevents a warning in the version of material-ui currently used.

Better info for workloads

For some reason the plugins were being reinitialized when the theme
was changed which also ended up in a reload of all components. This
shouldn't be needed, so this patch removes that logic.

We had an issue related to re-initializing the plugins when they've
already be initialized, this ended up re-registering the same plugin
functionality and thus would result in getting duplicated sections
and potentially other issues.

While re-initialization of plugins should be avoided altogether, the
logic for initializing them should make sure the plugins and their
states are reset before initialization which is what this patch does.

We may need the initial states for the different reducers to be
used again (e.g. to reset the initial state), so we shouldn't provide
a shallow copy of it as the initial state.

frontend: Fix applying non-grouped API resources

This prevents the issue of calling a function on a variable that may
be undefined.

Some APIs do not have a group and we were parsing the YAML added to
the creation dialog in a way that it expected to have a group.

These include the owned pods, containers, and details view plugin
renderer sections.

This will be useful to understand e.g. why pods are pending.

This allows us to show the controlled jobs, the schedule with a
human-readable description, etc.

The last scheduled time was not using the "time ago" way and therefore
was very confusing. This patch also adds an icon to the schedule
(cron) with a description of it on hover.

There was a bug where such statuses were being shown with the warning
theme.