[TASK] RTE: Split main JS script into components

Split the main script one class per file.

Releases: master
Resolves: #62404
Change-Id: Ide50dcae24339f7af4fbe4128b7947430af5db8f
Reviewed-on: http://review.typo3.org/33477
Reviewed-by: Stanislas Rolland <typo3@sjbr.ca>
Tested-by: Stanislas Rolland <typo3@sjbr.ca>