[TASK] Add option counter to LiveSearch

The option dropdown in LiveSearch now has a counter indicating the
number of active search options.

Resolves: #100017
Releases: main
Change-Id: I252c699dcb17318ccfcaa622d69b0ffd6ccf1901
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/77935


Tested-by: core-ci <typo3@b13.com>
Tested-by: Simon Schaufelberger <simonschaufi+typo3@gmail.com>
Reviewed-by: Simon Schaufelberger <simonschaufi+typo3@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>