1. The word "class" is a pain point with many languages where
it's a keyword. Type is a little better. Also, the property
was already named "device_type" and not "device_class".
2. Remove Efl.Input.Device.Sub_Class
It's not used inside EFL upstream codebase, and unlikely to
be used anywhere else (even in Tizen).
Hopefully no one used the Efl_ enum types. So far only the Evas_
types should be in used.
Ref T5540
Those are now merged with Efl.Object parent, name and comment.
The reasoning is that only seats can be parent devices; And name
and description are not only name clashes but also not extremely
useful anyway.
Tested with VNC.
Fixes T5540
If not provided, FOCUS_OBJECT action will keep acting
over default seat.
Also include a usage on edje-multiseat test
(actually no example was exercising this action).