feat: Add idle detection to collaboration feature (#2877)

* Start idle detection implementation

* First working version

* Add screen state

* Add type safety

* Better rendering, enum types, localization

* Add origin trial token

* Fix

* Refactor idle detection to no longer use IdleDetector API

* Cleanup some leftovers

* Fix

* Apply suggestions from code review

* Three state: active 🟢, idle 💤, away ⚫️

* Address feedback from code review
Thanks, @lipis

* Deal with unmount

Co-authored-by: Panayiotis Lipiridis <lipiridis@gmail.com>

src/excalidraw-app/collab/Portal.tsx

@@ -9,6 +9,7 @@ import CollabWrapper from "./CollabWrapper";
 import { getSyncableElements } from "../../packages/excalidraw/index";
 import { ExcalidrawElement } from "../../element/types";
 import { BROADCAST, SCENE } from "../app_constants";
+import { UserIdleState } from "./types";
 
 class Portal {
   collab: CollabWrapper;
@@ -132,6 +133,23 @@ class Portal {
     }
   };
 
+  broadcastIdleChange = (userState: UserIdleState) => {
+    if (this.socket?.id) {
+      const data: SocketUpdateDataSource["IDLE_STATUS"] = {
+        type: "IDLE_STATUS",
+        payload: {
+          socketId: this.socket.id,
+          userState,
+          username: this.collab.state.username,
+        },
+      };
+      return this._broadcastSocketData(
+        data as SocketUpdateData,
+        true, // volatile
+      );
+    }
+  };
+
   broadcastMouseLocation = (payload: {
     pointer: SocketUpdateDataSource["MOUSE_LOCATION"]["payload"]["pointer"];
     button: SocketUpdateDataSource["MOUSE_LOCATION"]["payload"]["button"];