To be deleted bitstreams are not highlighted in administer view

[tinsch]

Describe the bug

When you mark bitstreams for deletion in admin view, they are not highlighted in red, although the table is in table-danger css mode. Only a slight border highlighting happens, but it is nearly invisible. This seems to be some kind of bootstrap bug and the issue is similar to #5879

This issue is on the one hand a small bug but on the other hand a bigger UX issue, since users can not clearly see which bitstreams are marked for deletion before they actually remove them. This can lead to unexpected file loss.

To Reproduce

Steps to reproduce the behavior:

1. Login as administrator
2. Go to an item -> Administer Item -> Bitstreams tab
3. Mark one or more bitstreams for deletion and notice that they are not highlighted.

Expected behavior

The bitstreams that are marked for deletion should be highlighted in red, so the user does not delete the wrong bitstreams acidentally.

Related work

#5879
#5880