xwayland: Handle Xvisit finishing before drop
requested to merge work/zzag/xwayland-handle-xvisit-getting-cooked-earlier-than-expected into master
Xvisit::drop() has an assert to confirm that the drop operation occurs before the X visit is finished, and it seems like there are instances where the assert statement gets triggered, see the linked sentry crash report.
It appears like XwlDropHandler will start listening to the Xvisit::finish signal only after the X visit is left, for example when the cursor moves to another window.
This change ensures that the XwlDropHandler will listen to the finish signal right after creating the Xvisit object.
SENTRY: KWIN-37K