y-http provider to replace y-websocket and websocket polyfill

[max-nextcloud]

Is your feature request related to a problem? Please describe.
The yjs provider that syncs with the server is way to complex

Describe the solution you'd like
Have a y-http provider that takes care of the syncing and can handle being online / offline well.

y-http

• open connection
• expose connection
• basic syncing
• basic awareness messages
• include url in connection
• expect client to know params to open
• use ydoc client id in open
• handle awareness queries (without sending them)
• delay test requests
• ensure awareness messages are send at least every 10 seconds
• return only newer messages in DummyServer
• hand version to sync request
• ensure old awareness states are cleared after 30 seconds
• implement closing the connection
• test reopening the connection

embedding in text js

• implement client to instantiate y-http with
• extract api calls from Sync service and use connection instead
• extract document flags such as hasOwner from sync service and use them
• implement events in y-http provider and handle them instead of sync service events

server side

• allow flagging updates as full compressed history
• at most send all versions since last compressed one
• clean up older versions

later

• process queries
• send query message with every request
• send compressed history
• make the api stateless, removing the need for connection
• reset remote doc when receiving compressed history
• detect out of sync and reconnect (effectively receiving compressed history and all steps since then)
• handle sync queries (without sending them)