feat: Document presence indicator (#1114)

* Update websockets to allow joining document-based rooms

* dynamic websocket joining

* emit user.join/leave events when entering and exiting document rooms

* presence storage

* feat: frontend presence store

* lint

* UI updates

* First pass editing state

* refactoring

* Timeout per user/doc
lint

* Document data loading refactor to keep Socket mounted

* restore: Mark as viewed functionality
Add display of 'you' to collaborators

* fix: Socket/document remount when document slug changes due to title change

* Revert unneccessary package update

* Move editing ping interval to a shared constant

* fix: Flash of sidebar when loading page directly on editing mode

* separate document and revision loading

* add comments for socket events

* fix: Socket events getting bound multiple times on reconnect

* fix: Clear client side presence state on disconnect

* fix: Don't ignore server side error
Improved documentation

* More comments / why comments

* rename Socket -> SocketPresence

* fix: Handle redis is down
remove unneccessary join

* fix: PR feedback

app/scenes/Document/components/LoadingPlaceholder.js

@@ -12,10 +12,10 @@ const randomValues = Array.from(
   () => `${randomInteger(85, 100)}%`
 );
 
-const LoadingPlaceholder = (props: Object) => {
+const LoadingPlaceholder = () => {
   return (
     <Wrapper>
-      <Flex column auto {...props}>
+      <Flex column auto>
         <Mask style={{ width: randomValues[0] }} header />
         <Mask style={{ width: randomValues[1] }} />
         <Mask style={{ width: randomValues[2] }} />