integrate delayed blocklist submission with reviewer tools

[eviljeff]

part of https://mozilla-hub.atlassian.net/browse/AMO-43

The blocklist submission tool now supports delayed blocks, so we want to integrate this with the reviewer tools so, for example, the delay days amount can be set with the review.

┆Issue is synchronized with this Jira Task

[eviljeff]

Unblocked and I started working on this. Current flow is:

• reject_latest_version and reject_multiple_versions actions will do the usual things, but then also create a BlocklistSubmission object directly within the reviewer tools (no admin redirect) if the "Block" option is enabled on the form.
• If the block would require sign-off (high ADU) it's held until that sign-off has been given.
• if the block is delayed (and this is where it starts to get tricky) we create a BlocklistSubmission with a delay, but we can't just have it proceed as a normal delayed submission as a) delayed_rejections can be cancelled and b) delayed_rejections can be held back if there is a new version submitted in the mean-time.
  • so when the delayed time limit comes up and the cron picks it up it checks if all the versions are still marked as delayed rejection; if they're not but not rejected the submission is cancelled; if they're not but rejected the blocksubmission goes ahead. (and if they are still marked as delayed rejection the submission is skipped until the next time the cron runs)

I think this covers all the cases - ideally we'd rely on signals for the reviewer flags but there are classes of undefined behavior because the auto_reject task doesn't "group" rejections like the blocklist submission does - it just rejects whatever is pending for that add-on that fits the other criteria. It's still an option though.

@wagnerand what permission (if any beyond normal reviewer perms) will be needed to create the blocklist submission from the reviewer tools like this?