Editor selectionUpdate event fires when another user moves their cursor (via CollaborationCursor)

[jamesopti]

Description
When using the CollaborationCursor extension, the selectionUpdate event fires when another user is moving their cursor around in the doc.

editor.on('selectionUpdate', () => {
  // This will fire if another user clicks around the doc in their own browser 
})

Steps to reproduce the bug
Steps to reproduce the behavior:

1. Setup the basic CollaborationCursor demo
2. Add a listener for editor.on('selectionUpdate', onSelectionUpdate)
3. Open 2 browsers and click around in 1
4. Observe both clients firing the event handler

Expected behavior
While it may technically be true that the selection is changing, it would be nice to know if the event is firing due to this client or another.

Suggested API - If there is a notion of this client's id, passing that along would allow filtering. Otherwise, just isThisClient would suffice

editor.on('selectionUpdate', ({ editor, clientId or isThisClient }) => ...)

Additional context
Add any other context about the problem here.

[philippkuehn]

I’ve added the current transaction to the selectionUpdate event so you can check for remote changes now.

import { ySyncPluginKey } from 'y-prosemirror'

new Editor({
  onSelectionUpdate: ({ transaction }) => {
    // ignore changes made by y.js
    if (transaction.getMeta(ySyncPluginKey)) {
      return
    }

    console.log('selection update')
  }
})