Added deletion_comment param to CategoryMoveRobot

deletion_comment is added for merging
CategoryMoveRobot and CategoryRemoveRobot,
deletion_comment replaces useSummaryForDeletion
and does much more.
It has 3 options:
1. Plain string for deletion comment.
2. Same comment as used as move summary.
3. Automatic message.

Change-Id: I9a1c0ceb0a2de4ed1f4e87ab83b1e590d1843d40