We'd like to add a new command to RBTools for performing reviews, which

itself would actually be several commands. This might be useful for some

users who are super heavy command-line users, and would definitely be

useful for people who want to add automation of various sorts (such as

adding reviews after running custom CI tools that we don't have

integrations for). This review request is dependent upon the JSON output object from r#11521.

Manually tested all commands so far and documented on Notion. Also added and ran new tests in rbtools/commands/tests/test_review.py.