feat(ai): add ai text generation and rewriting using insights endpoint

[palmer-cl]

Adds the v1 functionality for AI Writing and Re-writing

• Adds AI button to the toolbar
• Adds custom popout styled menu when button is hit
• Adds AI layer component to handle highlighting (similar to comments layer)
• When suggesting, generated text are inserted as tracked changes
• Adds AI button to side tools menu

Requesting eyes on

• Emitting and Listening for events (specifically emitting from toolbar vs superdoc or if we could optimize this)
• AIWriter component is built in SuperEditor and then exported to SuperDoc. It is consumed by both. Is there a better pattern for this? Do we have a place we store shared components?

Caveats

• The processStream function will change when the insights endpoint update the data structure returned. This is in progress by @falsaadehh

[harbournick]

See my comments below. We currently try to keep a separation between what is Editor.js and what is SuperDoc which is not necessarily obvious.

[harbournick]

@palmer-cl and I discussed my comments, and we will move forward after @artem-harbour's review without architectural changes, and I will make the necessary changes in an additional PR.

[palmer-cl]

@harbournick it looks like c6db2d3 caused the e2e tests to fail. The reactivity chain may have been altered slightly when moving the state variables and refs into a composable pattern. Would you mind confirming if we should update the test, or change the code.

[artem-harbour]

LGTM

@harbournick, approved from my side, please double check everything from your side.

[harbournick]

LGTM

[harbournick]

Thanks for all the hard work on this one @palmer-cl !

[palmer-cl]

Thanks @harbournick and @artem-harbour ! Credit to the complete team effort!