[BUGFIX] Add returnUrl to records opened by EXT:opendocs

If a record that was opened by the opendocs menu gets closed, the user
now gets the record list of the record's pid.

Resolves: #77675
Releases: master, 7.6
Change-Id: I90014ea639ce191ad0ee2d1a1cd650d2aaaebc52
Reviewed-on: https://review.typo3.org/49627


Tested-by: Bamboo TYPO3com <info@typo3.com>
Reviewed-by: Philipp Gampe <philipp.gampe@typo3.org>
Tested-by: Philipp Gampe <philipp.gampe@typo3.org>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>