Refactor Customer and User Repository Methods for ObjectID Handling

- Updated GetByIDs methods in customer and user repositories to convert string IDs to bson.ObjectID, ensuring proper handling of MongoDB object IDs.
- Enhanced error handling for ID conversion to provide clearer feedback when invalid IDs are provided.
- Modified notification service calls in customer and user services to use context.Background() for asynchronous email sending, improving concurrency management.
- Ensured consistent handling of company IDs in the customer repository for retrieving customers by companies.

internal/user/repository.go

@@ -218,7 +218,16 @@ func (r *userRepository) Delete(ctx context.Context, id string) error {
 
 // GetByIDs retrieves users by IDs
 func (r *userRepository) GetByIDs(ctx context.Context, userIDs []string) ([]User, error) {
-	users, err := r.ormRepo.FindAll(ctx, bson.M{"_id": bson.M{"$in": userIDs}}, orm.NewPaginationBuilder().Limit(len(userIDs)).Build())
+	objectIDs := make([]bson.ObjectID, 0)
+	for _, id := range userIDs {
+		objectID, err := bson.ObjectIDFromHex(id)
+		if err != nil {
+			return nil, err
+		}
+		objectIDs = append(objectIDs, objectID)
+	}
+
+	users, err := r.ormRepo.FindAll(ctx, bson.M{"_id": bson.M{"$in": objectIDs}}, orm.NewPaginationBuilder().Limit(len(userIDs)).Build())
 	if err != nil {
 		return nil, err
 	}