Make editing actions of pending comments consistent with writing comments

Summary

The actions available when editing a pending comment are not the same actions available when writing a comment.

Steps to reproduce

1. In a merge request, reply to an existing thread.
2. Add that reply to a review by pressing Start review or Add to review.
3. Edit that reply and notice the bug.

What is the current bug behavior?

When editing a pending comment, there's just one button that both comments and resolves. So there's no possibility to indicate if the comment should resolve or unresolve the thread.

What is the expected correct behavior?

Editing a pending comment should be consistent with writing a comment, where there's a checkbox to resolve/unresolve the thread and a button to comment now.

Output of checks

This bug happens on GitLab.com