Notify when an installed, but disabled incompatible / `untested` app gets a compatible release

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Is your feature request related to a problem? Please describe.
When the NC core is updated, it isn't uncommon that a few apps are in the 'untested' state. Typically, I leave the untested apps in the disabled state because stability is more important than features. Then at some point, the app gets updated or is marked stable. The issue is the admin isn't being sent an admin notification that the app is marked stable now. So the admin has no clue that the wanted feature is stable again so it can be re-enabled.

Describe the solution you'd like
Send an admin notification when an untested app, enabled or disabled, moves from the untested state to the stable state.

Describe alternatives you've considered
#19044 - I don't think updating apps without admin interaction is a good thing.

Additional context
Add any other context or screenshots about the feature request here.

Start by locating the code that evaluates installed apps as untested or stable and the code that sends admin notifications. Confirm the behavior for both enabled and disabled apps, then verify that a transition from untested to stable produces an admin notification without automatically enabling or updating the app.