[TASK] Remove unused code

Remove all reflection classes and replace usage in Tests

Resolves: #58251
Resolves: #58254
Releases: 6.2
Change-Id: I09c066ae2cbd3e104b8d3982e5a50ee381872ac9
Reviewed-on: https://review.typo3.org/29754
Reviewed-by: Nico de Haen
Tested-by: Nico de Haen