Wayland in particular sets surface_capabilities.currentExtent.width to
the special value 0xFFFFFFFF, which is valid per spec.
Fixes#98779
It may also fix misc issues when resizing on all platforms.
Superseedes PR #98780 , thanks to user tdaven for the original patch.
PR #98780 would break Android support as it did not account that width
and height might need to be swapped.
Replaced manual swap by Godot's SWAP(), which indicates intention much
easier.
a5070af460