[TASK] Add functional tests for indexed_search

Added tests for:
- indexing contents and words
- a basic search
- metaphone search

Resolves: #97732
Releases: main, 12.4
Change-Id: Id56e09f129de4bd13092f584e97eedc9fd326b5c
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/79691


Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>