Make DispatchProxy declares Property/EventInfos of the interface.

Make DispatchProxy declares Property/EventInfos of the interface.

This commit adds code to declare properties and events
to generating proxy type as well.

Note
* Because declaring properties and events requires accessor methods,
  this commit changes AddMethodImpl to return created MethodBuilder.
* This declares EqualityComparer for MethodInfo to avoid reference based
  comparison.
* The test case now uses System.Reflection.Emit to generate the event
  with raise_ method which is not supported in C#.

Commit migrated from https://github.com/dotnet/corefx/commit/e8f650d67a67003786c04b916dc4805678237c0a