Review: Allow plugins to be moved from `rejected` to `pending`, and `pending` to `new`

[dd32]

The plugin directory currently has a very firm progress of post_status, which is a good thing in many cases, but.. sometimes human things happen..

It would be nice if we could un-reject a recently rejected plugin, when the author responds to the rejection email. We can't un-send the email, but it means we can finish a review "easier".

It would be nice if we could move a plugin back to new from pending when we accidentally move the plugin to pending (for example, from #6635) OR when a reviewer has to abort a review to hand it off to someone else.

[dd32]

It should be noted that this could make the stats a bit funky if a plugin was pulled from rejected after months, or a pending plugin pushed back to new after 2 months.

For that reason alone, I'd probably suggest this be limited to 7 days (or so) after the last status change. For pending -> new this could even be measured in hours, as this would currently affect the estimated queue length time (because we don't exclude outliers in the calculations there)

[dd32]

In 13507:

Plugin Directory: Allow reviewers to move a plugin from pending (Pending developer feedback) back to new (Pending initial review), and from rejected back to pending (Pending developer feedback)

Fixes #7386.

[dd32]

In 13512:

Plugin Directory: Add missed changes in [13507].

See #7386.

[dd32]

In 14333:

Plugin Directory: Correct a variable typo in the plugin rejection restoration process.

See #7386, [13507].