Instead of using a Grid, just use a Typography element. This prevents
the icon from wrapping when there's not enough space.

This patch also clarifies the icon's type and allows the caller to
set properties directly to the icon when differentiation is needed.

Since the ResourceTable allows to list resources in a more
homogenious ways, this patch replaces the SimpleTable uses by it in
many common places.

This component is the same as the SimpleTable but with a couple of
improvements to make it easier to use with kubernetes resources.
i.e. it allows to use certain types as columns, like "age" and "name"
which will translate into the commonly used age and name columns
respectively.

It can also be used with a resource class directly, allowing the user
to skip getting the list of resources + error before listing them.

javascript-time-ago's new releases no longer support the time format
(at least not easily), and also the new package is much lighter than
the former.

backend: Add proxy endpoint that forwards all request to provided URL

plugins/headlamp-plugin: Bump version to 0.5.1

frontend: Show containers' ports in UI

charts: Update Headlamp to 0.11.1

This is in the pods' details view.

Width cosmetic fixes

frontend headlamp-plugin: Audit fix dependency updates

Wait for plugins to load before showing views

So they wrap in smaller resolutions.

When the sidebar is the narrow version (when width=sm), then we should
always show the navigation tabs, otherwise the user has no way to
navigation.

The sidebar button (Headlamp icon by default) was also active even
when in the narrow sidebar version mode, meaning it would toggle the
navigation tabs, so this patch also prevents that by disabling the
button in that mode.

We allow the sidebar to be opened on any width other than sm, but the
main component was adding an extra margin between that measure and md
which resulted in an extra and useless blank space.

These changes add that margin only on sm.

It's no longer needed since the component where it's displayed already
wraps its values.

Fix routes

This patch changes the createRouteURL to be able to keep any passed
cluster name in order to create the route (before it was checking the
currently set cluster).

This will make it more flexible and also allow the function to be used
in tests.

The listRoute getter in K8s classes should be the name of the route
but in the case of the CRD class it was being used as the URL itself.

By mistake the latter has been changed to use the plural name.

Fix applying ingresses

Add error handling/boundaries for plugins

Stopped plugins with errors crashing Headlamp:
- On plugin load (script syntax error, or other error)
- When components are rendering

Extracted plugin loading and executing into a Plugins component.

Wrapped ErrorBoundary around where plugins can insert components
into the app.

Plugins are initialized, not reset, so action renamed to match.

Fixes #454