Switching between read/edit permission should update remote clients in realtime

[tommoor]

When updating the document permission of a user it should update their permissions in realtime without needing to reload the tab.

Follow on from #2359

[linear]

OLN-221 Switching between read/edit permission should update remote clients in realtime

[almereyda]

Testing this with 2505fea and two different users in different browser contexts yesterday and just now reveals that this already works in direction of

• edit to read

An eventual client will update the document state and switch to a read-only view.

Switching from

• read to edit

requires the reload.