Bug 34080: Make suggestions_batch_ops a class

Bug 34080: Make suggestions_batch_ops a class

To test:
1. Make some suggestions with different statuses.
2. Try moving some suggestion to different statuses.
3. Going from PENDING to another status works fine.
4. Moving from other status (REJECTED, ORDERED, etc ) will cause a 500 error.
5. Apply patch
6. Try 2 - 4 again, no more 500 errors, yay!

Signed-off-by: Sam Lau <samalau@gmail.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>