add: contactController,tests & refactored tests

internal/services/user_service.go

@@ -34,8 +34,7 @@ func (service *UserService) RegisterUser(user *models.User) (int64, string, erro
 	}
 	user.Salt = base64.StdEncoding.EncodeToString(salt)
 	*/
-	err := validateRegistrationData(user)
-	if err != nil {
+	if err := validateRegistrationData(user); err != nil {
 		return http.StatusNotAcceptable, "", err
 	}