Review Revision capabilities implemented in the Custom Stage for API 2

[racheljsmart]

The Review Revision Stage is run when PCs want to add new fields to a review for reviewers to fill out usually after the rebuttal period. These new fields are often the final rating of the paper and the justification for changing the rating. This is not implemented in api 2.

• [x] Add capabilities to the custom stage to allow PCs to mimic the functionality of the review revision stage (add fields to review note, limit fields that can be edited by reviewers, add task to reviewer tasks)
• [ ] Create documentation to guide PCs on how to use the custom stage to implement review revisions

This issue was reported by a user #129

[adinriv]

In addition to adding the "review revision" task to the reviewers console, it will be helpful to have a change in the interface to pre-emptively indicate the reviewers that their action in the review is needed. For instance, highlighting the review, or placing a highlighted comment on top that points them to edit the review.