plugins/headlamp-plugin: Add upgrade command

plugins: Add useClusterURL, noAuthRequired to sidebar example

- Warns if @kinvolk/headlamp-plugin is not up to date
- Upgrades @kinvolk/headlamp-plugin if it is outdated
- Adds missing config files added in recent versions
- Adds updated package.json config keys added in recent versions

Since the plugins are tested in that job, and if they are changed
we want the tests to run too.

headlamp-plugin: Convert tests to js from bash

plugins/headlamp-plugin: Bump version to 0.5.2

charts: Bump Headlamp to 0.12.0

app: Bump Chocolatey's Headlamp version to 0.12.0

Fix frontend version

frontend headlamp-plugin: Add material ui labs

Improve app menus

It was setting the submenu in the wrong object.

Some menus shouldn't be shown until we're sure plugins may have
changed them. This is particularly important for menus such as help,
which may carry brand-related actions, like opening the app's website,
etc.

To ensure this, this patch adds the ability to mark menus as to be
loaded only after plugins, which will give the opportunity for plugins
to change them if needed.

Even though we have translations for the default menu items, because
of the way the mechanism for overriding menus is done it means that
we'd always keep the English menu even for default items when the
menu was overridden (even without changing any of the items) by a
plugin.

This patch prevents that by updating the menus' labels with the
translated ones, using a new "id" for each default menu in order to
match the labels.

Instead of showing "Hide Headlamp", we should just show "Hide" as this
will work even if the product name has been changed.

And defaults to adding the default ones if they're not.
This patch also changes the logic for setting menus coming from
plugins, to use this function instead of repeating part of its code.

The i18n is a module global object, so we can just use it without
passing it.

Why useClusterURL?

noCluster is confusing because it's a negatively named variable
useClusterURL is used elsewhere (when registering sidebar entries)
useClusterURL has URL in the name, so it's a bit more descriptive

frontend: Ensure timeAgo always uses the date + 90 days when testing

We need to compare static dates when testing, otherwise snapshots
become outdated.

frontend: Catch and log Plugin initialize() errors

frontend: Fix Plugin class based plugins not loading

So that plugins that use initialize() will not crash the system
if they have an error in them.

frontend AlertNotification: Fix rule-of-hooks issues

Was causing an error in the app.