[TASK] Move getUserWhoDeleted function to RecordHistory

In ext:recycler, there is an open todo to move the function
`getUserWhoDeleted` from `RecyclerAjaxController to `RecordHistory`.

This change moves the function to `RecordHistory` and additionally
renames it to a more appropriate name.

Resolves: #103474
Releases: main
Change-Id: Id49d2e42c6c2393ef6c0b888bf293cd835cca1ed
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83578


Reviewed-by: Simon Schaufelberger <simonschaufi+typo3@gmail.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Simon Schaufelberger <simonschaufi+typo3@gmail.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: core-ci <typo3@b13.com>