[BUGFIX] EM: Add return link to showAllVersions

Extension manager ShowAllVersions view does not deliver
link to return to the TER list. The return link is added.

Change-Id: Iaf266203222416d4c5656d5d52927c0b750b8860
Fixes: #46938
Releases: 6.0, 6.1
Reviewed-on: https://review.typo3.org/19586
Reviewed-by: Sascha Egerer
Tested-by: Sascha Egerer
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn