fix: Various fixes for collaborative editing beta (#2561)

* fix: Remove Saving… message when collab enabled

* chore: Add tracing extension to collaboration server

* fix: Incorrect debounce behavior due to missing timestamps on events, fixes abundence of notifications when editing in realtime collab mode

* fix: Reload document prompt when collab editing

server/collaboration/logger.js

@@ -0,0 +1,22 @@
+// @flow
+import debug from "debug";
+
+const log = debug("server");
+
+export default class Logger {
+  async onCreateDocument(data: { documentName: string }) {
+    log(`Created document "${data.documentName}"`);
+  }
+
+  async onConnect(data: { documentName: string }) {
+    log(`New connection to "${data.documentName}"`);
+  }
+
+  async onDisconnect(data: { documentName: string }) {
+    log(`Connection to "${data.documentName}" closed`);
+  }
+
+  async onUpgrade() {
+    log("Upgrading connection");
+  }
+}