[BUGFIX] EXT:form - open the ElementBrowser in modal window

Migrate the JS ElementBrowser to the modal which was introduced with
issue #82427.

Resolves: #82443
Releases: master
Change-Id: Ib71a15a7ce9638de4eb423d896fefa47bfa15e96
Reviewed-on: https://review.typo3.org/54115


Reviewed-by: Bjoern Jacob <bjoern.jacob@tritum.de>
Tested-by: Bjoern Jacob <bjoern.jacob@tritum.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>