[FEATURE] Hide delete button if soft reference exists to Asset

Change-Id: I3b3608c5e59dbaddccd97f80711a7629c782b50b
Releases: 2.0.0
Resolves: #54350
Reviewed-on: https://review.typo3.org/26351
Reviewed-by: Fabien Udriot
Tested-by: Fabien Udriot