Support xdg_toplevel_tag_v1

[vaxerski]

This is a general discussion regarding xdg-toplevel-tag-v1

I wonder if it has any use in Hyprland. Possibly as a windowrule, but anything else? Maybe it could fix the firefox pip rules once and for all (if firefox implements something correctly for once)

[vaxerski]

added in d5638e9