evas: Replace Evas.Modifier_Mask with Efl.Input enums

evas: Replace Evas.Modifier_Mask with Efl.Input enums

This removes Evas.Modifier_Mask from EO.

This introduces two new types instead:
 - Efl.Input.Modifier
 - Efl.Input.Lock

Those are enums, not strings, containing all the known and
currently supported lock and modifier keys. The enums are
bit masks.

This effectively removes the ability for an application to
create and handle specific modifier or lock keys - with EO
API (legacy compatibility is unchanged, of course). I wonder
who ever required this?