[BUGFIX] Avoid getTCAtypeValue-calls in DataHandler->fillInFieldArray

DataHandler->fillInFieldArray fetches BackendUtility::getTCAtypeValue
for each record but uses the value only if several RTE-transformation-
related conditions are met.

Fetch BackendUtility::getTCAtypeValue only if the RTE-transformation-
related conditions are met for the first time and keep it afterwards.

Resolves: #63728
Releases: master, 6.2
Change-Id: I14b307c45cab2d778968f3fd98c18348b666be3d
Reviewed-on: http://review.typo3.org/35227


Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>
Reviewed-by: Benjamin Mack <benni@typo3.org>
Tested-by: Benjamin Mack <benni@typo3.org>