New Permission: "Spoiler Post"

It would be very useful for Moderators (or more accurately - certain roles) to be able to spoil and add a Content Warning to posts that are not their own.

I understand why moderators can't edit posts, but personally I've found people tend to just delete posts or get busy and not respond when something sensitive doesn't outright need removal, but does need to just be spoiled and have a small CW or context added. Sometimes discussions start moving quickly and people forgot to spoiler something (whether that be about a piece of media, a more serious personal discussion about upsetting topics, or memes that are just a little too spicy for a given channel).

This permission would:

Add a new option to the drop down called “add CW”

Upon clicking this, the post (or image) is converted to a spoiler, with the CW in front (e.g. CW: gore, or even just CW: spoilers for movie <X>). To prevent abuse and confusing whose words were what, an icon is added to the post near where “edited” is specifying which moderator did the action.

Functionality questions:

Q: What if the post already contains a spoiler, just not in the relevant part?

A: All existing spoiler tags are stripped and theyre added to the whole post

Q: What if the user wants to go back to edit a post that a mod CWd?
A: The user is free to remove the CW from the text and edit the spoiler to their liking, upon doing so the “edited by moderator” tag is removed and replaced with the normal “edited” tag, because the user has essentially “signed off” on the edit.

Q: What if a user is editing a post that gets CWd by a mod?

A: Same as a post getting deleted - the user gets booted out of the edit.

Q: Does there *have* to be a CW/context added?

A: No, a blank entry would be accepted and would simply convert the post to a spoiler with no warning.

Q: Can there be a spoiler *in* the CW itself?

A: No, spoilers are stripped from CWs, to prevent confusion over what spoiler the CW applies to.

Q: Why not allow moderators to spoiler only part of a post?

A: Too complicated to implement without just allowing moderators to edit other users' posts wholesale, which opens up a giant can of worms. Forum software like vBulletin gave moderators this permission and it can be used well, but is incompatible with Discord's philosophy up to this point. This provides a means to do some minor moderation action without giving moderators the ability to put words in peoples mouths or entirely butcher somebody's posts in a moment of anger.