Prevent rich-formatting paste

[mary-ext]

Fixes #1321
Fixes #3032
Fixes #4301

We don't actually support rich WYSIWYG formatting in the composer, check if what's being pasted is one, and retrieve a plain-text version of it. This won't interfere with pasting HTML files (even though that's not supported either) as pasted files only have Files in the types array.

[mary-ext]

Fix works for me, just need verification from others, easiest way to test is to have a fresh copy of Edge on Windows, and copy any links, like from the address bar.

[gaearon]

would be good to verify that the fix works, then we can pull it in.

[auroursa]

It seems to partially resolve the issue, but the link preview is not working (I'm not sure if this is the expected behavior).
By the way, the link I tested is https://github.com/bluesky-social, and my Edge version is 125.0.2535.85.

[boly38]

just some little note while reviewing your diff

[mary-ext]

It seems to partially resolve the issue

I'll take another look tomorrow to see if there's anything that can be done, don't want to resort to detecting links and snipping the rest of it off

[Zero3K]

I wonder how Twitter/Upwork does it. Maybe someone could look into that and then use either of their methods.

[mary-ext]

Looks like this is happening because .preventDefault() doesn't seem to prevent pasting, so we're still inserting the original pasted text, for some reason. I think this might be on ProseMirror though when I last looked at its code, so let me see.

[mary-ext]

Yup. https://github.com/ProseMirror/prosemirror-view/blob/9da2e4ed026971e39555336d176bab7047df2529/src/input.ts#L620

[mary-ext]

@auroursa Can you verify this again? I've confirmed that it works as it should on my end.

[auroursa]

@mary-ext Yeah it works very well for me.

[gaearon]

didn't test Edge but this does result in more sensible paste output on macOS when pasting HTML from random places, let's give this a try.