fix chat domain model

[SOunit]

• message should have user data for presentation layer

ASIS

export type Chat = {
  id: string;
  users: User[];
  messages: Message[];
};

export type Message = {
  id: string;
  userId: string;
  chatId: string;
  text: string;
  createdAt?: string;
};

TOBE

export type Chat = {
  id: string;
  userName: string;
  userImageUrl: string;
  messages: Message[];
};

export type Message = {
  id: string;
  chatId: string;
  userId: string;
  userImageUrl: string;
  text: string;
  createdAt?: string;
};