Enhance Customer Module with Validation and Username Handling

- Introduced a new ValidationService for customer operations to ensure valid username formats.
- Updated customer service and handler to utilize the new validation service, enhancing input validation during registration and updates.
- Modified CreateCustomerForm and UpdateCustomerForm to enforce username validation rules.
- Adjusted repository indexing to improve search efficiency by refining the text index for customer data.
- Ensured consistent handling of usernames across the customer module, improving overall data integrity and user experience.

internal/customer/handler.go

@@ -15,15 +15,17 @@ type Handler struct {
 	authService authorization.AuthorizationService
 	userHandler *user.Handler
 	logger      logger.Logger
+	validator   ValidationService
 }
 
 // NewHandler creates a new customer handler
-func NewHandler(service Service, userHandler *user.Handler, authService authorization.AuthorizationService, logger logger.Logger) *Handler {
+func NewHandler(service Service, userHandler *user.Handler, authService authorization.AuthorizationService, logger logger.Logger, validator ValidationService) *Handler {
 	return &Handler{
 		service:     service,
 		authService: authService,
 		userHandler: userHandler,
 		logger:      logger,
+		validator:   validator,
 	}
 }