Revision API: Add methods to get / set review status

File-path must be passed unencoded and will be handled in impl.

Change-Id: Ife5c2f21c2e916ed9cf73f4fa157b85a6dc4d485
Revision API: Implement methods to get / set review status

Change-Id: If68c43e94acdfcffd7b41e78179f5b2e3f83db48
Merge changes If68c43e9,Ife5c2f21

* changes:
  Revision API: Implement methods to get / set review status
  Revision API: Add methods to get / set review status