Refactor Notification Management and Enhance Customer Features

- Updated the notification handling logic to utilize a new SDK for sending notifications, improving the flexibility and scalability of the notification system.
- Introduced new methods in the notification service for sending notifications to users and customers based on various target audience types, enhancing the notification delivery capabilities.
- Added a new endpoint to assign companies to a customer, improving customer management functionalities.
- Refactored the customer entity and forms to replace 'CompanyIDs' with 'Companies', ensuring consistency across the data model.
- Enhanced API documentation with Swagger comments for the new endpoint and updated notification structures, ensuring clarity for API consumers.

internal/user/service.go

@@ -23,6 +23,7 @@ type Service interface {
 	Update(ctx context.Context, id string, form *UpdateUserForm) (*UserResponse, error)
 	UpdateStatus(ctx context.Context, id string, form *UpdateUserStatusForm) error
 	GetUserByID(ctx context.Context, userID string) (*UserResponse, error)
+	GetUsersByIDs(ctx context.Context, userIDs []string) (*UserListResponse, error)
 	Search(ctx context.Context, form *SearchUsersForm, pagination *response.Pagination) (*UserListResponse, error)
 	Delete(ctx context.Context, id string) error
 
@@ -250,6 +251,23 @@ func (s *userService) GetUserByID(ctx context.Context, id string) (*UserResponse
 	return user.ToResponse(), nil
 }
 
+// GetUsersByIDs retrieves users by IDs
+func (s *userService) GetUsersByIDs(ctx context.Context, userIDs []string) (*UserListResponse, error) {
+	users, err := s.repository.GetByIDs(ctx, userIDs)
+	if err != nil {
+		return nil, err
+	}
+
+	var userResponses []*UserResponse
+	for _, user := range users {
+		userResponses = append(userResponses, user.ToResponse())
+	}
+
+	return &UserListResponse{
+		Users: userResponses,
+	}, nil
+}
+
 // Search searches users with search and filters
 func (s *userService) Search(ctx context.Context, form *SearchUsersForm, pagination *response.Pagination) (*UserListResponse, error) {
 	// Get users