Efl.Ui.Button_NativeInherit -> Efl.Ui.Button.NativeMethods
Will help using EFL# with completion tools.
- Added pragmas around the native function definitions to avoid warnings related to the name of native functions
- Updated some style fixes for native function wrappers.
Their preamble and epilogue styling will be dealt with in future diffs.
As a side effect, concrete classes had to be made public again as they
hold the function pointers to the native methods of their interfaces.
Thus a third party library class that implements IFoo should be able to
access these methods.
Depends on D8622