Reorganize some classes after CS1 was removed

Some of these were shared between CS1 and the unified screen or
CS2. Now that CS1 is gone the "changes" package is mostly about
listing one or more changes in dashboards or search results.

Move code to "patches" (for unified) or "change" (for CS2).

Change-Id: Ia87183e1e8d105ea3894bb426432b10153205a6f
13 files changed