message: refactor: add some types
diff: @@ -14,7 +14,7 @@ const KEY_TYPE = 'clientAvatarType';
  const KEY_SESSION_FLAG = 'clientAvatar';
  export default class ClientAvatar {
  - private static instance;
  + private static instance: ClientAvatar;
  public static get(): ClientAvatar {
  if (!ClientAvatar.instance) {
  @@ -25,7 +25,7 @@ export default class ClientAvatar {
  }
  private elements = [];
  - private contact;
  + private contact: IContact;
  private constructor(private storage: Storage) {
  let accounts = Client.getAccountManager().getAccounts();
  