App menu: Make it easier to distinguish between templates and app qubes

[wondoketu]

The problem you're addressing (if any)

I have run into the following scenario a few times. Call it a consequence of being particularly clumsy.

I open a Qube Template and do some configuration. I shut it down so I can use an AppVM. Somehow by this point I forgot the state of my Qubes Application Menu which has left the TEMPLATES menu remain selected. I end up opening one of these TemplateVMs as if it were an AppVM. This is a security problem of course.

Proposed solutions

1. Default the menu state to remaining in the APPS submenu.
   or
2. Add some warnings that pop to the eye if the user is in the TEMPLATES state. Perhaps the whole menu gets a color update.

The first solution is the easiest, but the second one might just be a good idea in general. Remind users that they need to proceed with caution.

Here is a comparison with some crude editing:

Vanilla comparison between AppVM menu and TemplateVM menu

More distinguishable version

The value to a user, and who that user might be

Prevent user error that compromises security.

Completion criteria checklist

(This section is for developer use only. Please do not modify it.)