Add test/user of `PrAddUTHitsTool::getUTHits`

The following discussion from !2482 (merged) should be addressed:

• @cmarinbe started a discussion: (+4 comments)

  for my understanding, where is this method used? A grep in Rec, Phys, Moore and Alignment returns no matches. If it's not needed anymore, I'd suggest to simply remove it.

A test for this method exists only privately and needs to be added to Rec/Moore