[BUGFIX] ElementInformation: close href attribute in back button

Add missing closing quotation of href-attribute of back button.
Enable adding file reference after displaying detail view of a file.

Resolves: #71814
Releases: master
Change-Id: Idb4f14836f6df21aef0aa7ff1012250bf8990bee
Reviewed-on: https://review.typo3.org/44934


Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>