Refactor data-device
Various refactoring commits to improve our data-device implementation.
Breaking changes:
-
wlr_seat_client_send_selection
has been removed, this is an internal function -
wlr_data_source_finish
has been removed, this is now handled bywlr_data_source_destroy
-
wlr_data_source_cancel
has been renamed towlr_data_source_destroy