WikibaseRepo: Cleanup use section, comments and line lengths

I removed classes from the "use" section that are only used a
single time in a comment. In my opinion it doesn't hurt to have a
longer path in very few comments for the benefit of a much cleaner
"use" section.

Change-Id: Id7bca7eae7dfc7607311d6310024a0fa02f470df
Merge "WikibaseRepo: Cleanup use section, comments and line lengths"