[BUGFIX] RTE Image Wizard layout is inconsistent

Solution: Fix form markup inside table tag.
Remove old color class on labels.
Add rtehtmlarea skin file in order to size and position select and
checkboxes correctly in image update tab.
Position correctly window title.

Resolves: #55946
Releases: 6.2
Change-Id: I497c4a3005bd80b5b05edd64e7ebbca1dee3c0ce
Reviewed-on: https://review.typo3.org/27589
Reviewed-by: Stanislas Rolland
Tested-by: Stanislas Rolland