Persistent plugin author notifications

[dd32]

Sometimes plugins get closed without plugin authors being aware - such as when their email bounces, or their email address goes to a place where the author doesn't monitor. The plugin author usually then emails with a "Huh? Why didn't I get told?" or "Sooo I just found out my email was broken.. what do I do?", requiring plugin reviewers to then explain it to the author.

In those cases, and many others, it would be beneficial to to be able to add a persistent notification at the top of their plugins page explaining it to them.

This could be used both when the plugin is closed, or as a not-so-gentle reminder of "Please stop doing XYZ".

In the future, it could be extended to also be actionable alerts, but the PR I'm about to attach is a one-way communication method.

Trac Ticket: https://meta.trac.wordpress.org/ticket/6880

Examples	-
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Reviewer Flow	<video src="​https://user-images.githubusercontent.com/767313/227123924-157e2f1b-b1bb-4299-b7ee-5ccf22541134.mp4">
Error
Warning
Info

[dd32]

Let's see if this gets any useful feedback from plugin authors, whole bunch of plugins are going to be closed due to bouncing emails from the WP 6.2 emails.

Typo'd it in r12492

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Plugin Directory: Add ability to define a 'Plugin Author Notice' for plugins.

This is a notice that plugin reviewers can set, that is then visible on the plugins page by plugin authors/committers.

The intent is that this can inform plugin authors why their plugin has been closed when they miss the email.

Fixse #6880.
Closes ​https://github.com/WordPress/wordpress.org/pull/135.

[dd32]

In 12497:

Plugin Directory: Author Notice: Ensure that it always has a <p> element.

The notices look bad without at least one wrapping block element, and when copy-pasting from other sources contentEditable isn't always perfect.

See #6880.

[dd32]

In 12506:

Plugin Directory: Author Notice: Enforce a smaller set of HTML tags.

This results in <span>'s and various hidden styles from being saved.

See #6880.

[dd32]

Improvements:

• Being able to clear the alert without having to both clear it and set to no-show. (Currently clearing it will also turn it off, but that's not obvious)
• Templates for common responses