[TASK] RTE: Migrate toolbar button to plain JavaScript

Releases: master
Resolves: #63946
Change-Id: Ib9230c9b9317ced27f6b293514eacd98db1ba842
Reviewed-on: http://review.typo3.org/35532
Reviewed-by: Stanislas Rolland <typo3@sjbr.ca>
Tested-by: Stanislas Rolland <typo3@sjbr.ca>