[TASK] Indexed Search: Use DTOs for indexing data

Content parsers implemented in Indexed Search return a solely defined
array for the internal indexer. To streamline the data passing,
dedicated DTO classes are now introduced and used.

Resolves: #102908
Releases: main
Change-Id: Ib06df1b42e05338240c2e2c50f73d88f94bf551f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/82607


Reviewed-by: Garvin Hicking <gh@faktor-e.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Stephan Großberndt <stephan.grossberndt@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Garvin Hicking <gh@faktor-e.de>