🐛(frontend) fix bug multi ws connection

In collaborative mode, only the first document
connected was being shared. This was due to the
fact that the webrtc server was managing only
one connection at a time. This commit fixes this
bug by managing multiple connections.

src/frontend/apps/impress/src/features/pads/pad-editor/stores/usePadStore.tsx

@@ -24,7 +24,9 @@ const initialState = {
 export const usePadStore = create<PadStore>((set) => ({
   padsStore: initialState.padsStore,
   createProvider: (padId: string, initialDoc: Base64) => {
-    const doc = new Y.Doc();
+    const doc = new Y.Doc({
+      guid: padId,
+    });
 
     if (initialDoc) {
       Y.applyUpdate(doc, Buffer.from(initialDoc, 'base64'));