* Fix play button starting wrong beatmap before selection loads
When clicking the osu! cookie (play button) before a newly selected beatmap finishes loading, the previous beatmap would be played instead of the currently selected one.
This was caused by the cookie reading from the global beatmap state which is debounced by 150ms, while the Enter key correctly used the carousel's current selection.
The fix makes the cookie use the same beatmap source as Enter - the carousel's current selection - which is always up-to-date regardless of debounce timing.
Closes#36074
* Use ensureGlobalBeatmapValid() for logo and Enter key actions
* Add test for beatmap selection timing bug
Tests the fix for issue #36074 where clicking the play button immediately after selecting a different difficulty would start the wrong beatmap due to the 150ms selection debounce.
Additionally to fix the options button, I could either cache the
interface in PlaylistsSongSelectV2 or make the interface cache itself. I
went with the latter option.