[BUGFIX] Hide "Add media by URL" if maxitems count is reached

If you have a reference field and the maxitems count is reached,
the buttons for "Add media file" and "Select & upload files" are hidden
but the button to add a media url still remains.

This patch adds needed class and Javascript to hide the button as well.

Resolves: #70762
Releases: master
Change-Id: I237ca08990df25c411b533dd68fb2f2944678ae8
Reviewed-on: https://review.typo3.org/44649


Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>