create conversation should work with frontend objectIds

packages/core/models/conversation.model.ts

@@ -9,25 +9,31 @@ export default class Conversation {
      * includes basic user info as well as their information
      * for this particular conversation
      */
-    public members: (ConversationMember & User)[],
+    public members: ConversationUserMember[],
 
     public name?: string,
 
+    public id: ObjectId = new ObjectId(),
+
     /**
      * last time there was new content for everyone
      */
     public lastActivityDate = new Date(),
 
     /**
-     * when name was changed or member list updated
+     * when the conversation document was created
      */
-    public lastUpdatedDate = new Date(),
     public createdDate = new Date(),
 
-    public id: ObjectId = new ObjectId(),
+    /**
+     * when name was changed or member list updated
+     */
+    public lastUpdatedDate?: Date,
   ) {}
 }
 
+export type ConversationUserMember = ConversationMember & User;
+
 export class ConversationMember {
   constructor(
     public role: MemberRole,