[TASK] EM: extension info within "Get Extensions"

Improves the single view / showAllVersions with further details.
Brings detail view as a base for further improvements.

Change-Id: Ia774a064508d6e98438f6480d929e39cbe7e5534
Fixes: #39919
Releases: 6.0, 6.1
Reviewed-on: https://review.typo3.org/19609
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn