xdg-toplevel: introduce wlr_xdg_toplevel_state_request
This fixes issues with compositors which delay their configures (e.g. to update the layout atomically) and fixes sending two configure events for a toplevel that requests to be maximized/fullscreened before mapping.
Sway patch: https://github.com/swaywm/sway/pull/6868
Test client: https://paste.sr.ht/~vyivel/95a5f51d6d981cfe7053c58573f38476f77878d8
Only one configure must be reported.
Edited by Kirill Primak