I've noticed a couple of workflow issues working with the code review tool and would like to request some new features:

- Sometimes a reviewer will request changes that require a certain amount of back-and-forth, comments, etc. to address and it's not always clear when the CL is ready for review again. In my opinion, the reviewer should be able to mark a CL as "changes required", and it would remain in that state until either the CL is re-uploaded or the author re-requests review.

- Sometimes I'll upload a CL but realize I need to make changes. I should be able to mark a CL as "changes planned" to avoid wasting reviewers' time reviewing something I'm about to change.

- Sometimes a non-owner will LGTM a CL, and the tool will show it as green as if it's ready to be landed, and then either I'll forget I need an owner LGTM and waste time trying to land it and having the commit queue reject it, or the owner will start ignoring the CL because they think it's already been reviewed. Ideally the code review tool would be aware of the OWNERS lists and not show the CL as green in the list if more LGTMs are required. At the very least, the CL should not be green if I've marked a reviewer as required and that reviewer has not provided an LGTM.