[TASK] Allow to define multiple DataHandler commands for one element

The method DataHandler::process_cmdmap currently allows only one command
to be executed for one element. A command-map like the following is
currently not possible - the second command would be ignored:

[tt_content][13][localize] = 1
[tt_content][13][inlineLocalizeSynchronize] = children:14

Resolves: #71125
Releases: master, 6.2
Change-Id: I473ea0de3789d77cb913ad64a26a666ab73c2a52
Reviewed-on: https://review.typo3.org/44350


Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Tested-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>