refactor: reimplement realtime-communication

This commit refactors a lot of things that are not easy to separate.
It replaces the binary protocol of y-protocols with json.
It introduces event based message processing.
It implements our own code mirror plugins for synchronisation of content and remote cursors

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

commons/src/y-doc-sync/y-doc-sync-server-adapter.ts

@@ -0,0 +1,14 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { MessageTransporter } from '../message-transporters/message-transporter.js'
+import { YDocSyncAdapter } from './y-doc-sync-adapter.js'
+
+export class YDocSyncServerAdapter extends YDocSyncAdapter {
+  constructor(readonly messageTransporter: MessageTransporter) {
+    super(messageTransporter)
+    this.markAsSynced()
+  }
+}