Investigate perf with EF Core on MAUI

[Metritutus]

In developing a Xamarin Android app using Entity Framework Core 2.0 with a code-first approach using a Sqlite database provider, the initialisation time seems pretty slow. For approximately 40 models (and a practically empty database) the app takes around 14 seconds to launch, 10 seconds for the call to Migrate(), and another 3-5 seconds for the first query after that. Once those are done it seems to be fine. There's barely any difference in initialisation time between Release and Debug builds.

I'm not sure if it relates to #4372 or #1906, but it may well do.

Is there anything I can do to help mitigate the initialisation time?