Edit or retract an edit submission that hasn't been reviewed yet

[cellio]

https://meta.codidact.com/posts/283569

If you submit an edit and then want to edit it further (for example, you see a typo or the rendered output isn't right), you can't -- while your submission is pending, you can't edit again. Could we allow the author of a pending edit to update the edit suggestion? If that's too hard, can we give people a way to retract the edit suggestion so they can start over?

We currently allow a single reviewer to approve an edit, so this doesn't compromise approval integrity. If we ever require more than one reviewer, we'd want to either prevent this if there's an approval already or cancel the approval. But that's a future consideration, since we don't have multiple reviewers now.