[TASK] RTE: Remove dependency on Ext.EventManager.onWindowResize

Replace with plain JavaScript and jQuery handler.

Releases: master
Resolves: #63691
Change-Id: Ibb71856d8c2a7c1fb5f8e2bbeb43c8d4a0d36ed9
Reviewed-on: http://review.typo3.org/35174
Reviewed-by: Stanislas Rolland <typo3@sjbr.ca>
Tested-by: Stanislas Rolland <typo3@sjbr.ca>