fix/iOS: Load realm-wrapper DLL using MainBundle.PrivateFrameworksPath

[EmilienDup]

Using Reflection to evaluate MainBundle.PrivateFrameworksPath on iOS

Description

Fixes #3711
Allows Realm to work in net10-ios apps.

This change is minimal.
It is based on #3714 (comment)

Replaces #3714

TODO

• Changelog entry
• Tests

[nirinchev]

Most failures are red herrings due to GHA not liking an external contributor creating checks. The real issues are the wrapper builds for apple platforms and android. The apple builds should be fixed by realm/realm-core#8091, while for Android, we'll need to bump the runner (it's currently using ubuntu-20.04 which is no longer available).

[nirinchev]

I created #3719 - let's hope that resolves the CI issues.

[charlesroddie]

As noted in #3711 (comment), the issue is likely caused by Single-file apps no longer look for native libraries in executable directory .

The recommended action by Microsoft stated in this breaking change notice is this:

If the application/assembly directory is desired for a P/Invoke or native library load and wasn't previously specified, specify DllImportSearchPath.AssemblyDirectory.

This PR doesn't do this, so it shouldn't be merged.