[TASK] RTE: Move style sheets and images to Resources directory

Releases: master
Resolves: #62768
Change-Id: I6948bb97d156e47ab16f130a54785f55e7e6daac
Reviewed-on: http://review.typo3.org/33888
Reviewed-by: Stanislas Rolland <typo3@sjbr.ca>
Tested-by: Stanislas Rolland <typo3@sjbr.ca>