[BUGFIX] EXT:indexed_search: Use correct API to calculate icon path

This patch makes use of `PathUtility::getAbsoluteWebPath()` in
EXT:indexed_search's SearchController which is suitable for calculating
asset paths in both, Composer and non-Composer scenarios.

Resolves: #101727
Releases: main, 12.4, 11.5
Change-Id: I88f487b1fdf88b404fc51a3d5d6131dba5483cdc
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/80674


Reviewed-by: Benjamin Franzke <ben@bnf.dev>
Tested-by: Benjamin Franzke <ben@bnf.dev>
Tested-by: core-ci <typo3@b13.com>