Remove IModule and other classes from ReactUWP which moved to Microsoft.ReactNative

[jonthysell]

We don't need or want both, and it's confusing.

Also need to move to cppwinrt from WRL implementation

Also need to remove module.g.cpp. Currently we need to maintain it manually. So we should use the one in Generated Files folder.

[jonthysell]

This was addressed in #3809.