[BUGFIX] Allow setting onChange for category fields

When using `makeCategorizable` with options to overwrite the default
field configuration, onChange was not overwritten. This has now been
implemented.

Resolves: #84799
Releases: master, 9.5
Change-Id: If62dd0472be2214d02b3b6c538d5d35d6d41661a
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63873


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Guido Schmechel <guido.schmechel@brandung.de>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>