Look into using hosted services. This would replace the icky IMauiInitializeService that was added in #2137, and also to enable users to use hosted services. MAUI will automatically call StartAsync/StopAsync at the appropriate time. Sadly, this pattern is async-only, whereas in MAUI the call sites are always (or at least almost always) sync. But given that this is app startup/shutdown, doing async-over-sync might be OK (we would block).

This is a follow-up to PR #2137.

Other notes:

• Need to consider this when implementing: Run user defined hosted services before the server starts. aspnetcore#36122