[TASK] Live search placholder is hard-coded

Resolves: #71115
Releases: master
Change-Id: If7aa0e242c96f3f31db9fc67c6450b86fb0546c6
Reviewed-on: https://review.typo3.org/44344


Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>
Reviewed-by: Xavier Perseguers <xavier@typo3.org>
Tested-by: Xavier Perseguers <xavier@typo3.org>