Join a BlockNote realtime session without the lock confirmation

When a Page was already being edited with the BlockNote editor, the next user opening that Page for editing was asked to confirm that they want to take over the edit lock, even though both users were about to edit the Page together.

Now, as long as a BlockNote collaboration session is in progress on the Page, opening that Page with BlockNote joins the session directly, in both the in-place and the standalone edit modes, the same way realtime editing with CKEditor already did. The confirmation is still shown when there is no session to join, and when the Page is opened with another editor.