[BUGFIX] Set timeout for immediate debounced execution

Executing a debounced event listener immediately now sets a timeout to
wait until the next execution is invoked.

Resolves: #90809
Releases: master
Change-Id: I76622c62cacfcf82d737fd93ae5a96fa4e7485a3
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63843


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Susanne Moog <look@susi.dev>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Susanne Moog <look@susi.dev>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>