[BUGFIX] Prevent Media Picker to show up widely

The File Picker window should only pop up
where relevant (and not everywhere as currently).

This patch bring some discipline to the File Picker by checking
if the popup is of type inline which means a file will be picked.

Change-Id: Ib1fabeff0bc83d43fd4f746d4df41ff47ce2ba4b
Releases: 3.0
Resolves: #58812 #55506
Reviewed-on: https://review.typo3.org/30130
Reviewed-by: Fabien Udriot
Tested-by: Fabien Udriot