Resolve ILLink warnings in System.Reflection.DispatchProxy (#46715)
* Resolve ILLink warnings in System.Reflection.DispatchProxy
I also took this chance to remove unnecessary GetTypeInfo() calls, since some of them needed to be removed.
Contributes to #45623
* Update annotations for PR feedback.
Remove DynamicallyAccessedMemberTypes.All from the interface and base class types. If unused members are trimmed, this won't cause problems with DispatchProxy.
* Add a trimming test for DispatchProxy since we are suppressing ILLinker warnings.