Fix serialized name handling in validate_request decorator

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The previous implementation of the validate_request decorator did not correctly handle the serialized names of fields in the DTO class when populating attribute values from the request. This commit addresses the issue by updating the decorator to access the serialized names directly from the serialized_name attribute of each field.

The updated implementation iterates over the fields in the DTO class and checks for the presence of the serialized names in the request body. If a matching serialized name is found, the corresponding value is assigned to the DTO attribute. This ensures that fields with serialized names, specified using the serialized_name parameter in the field definitions, are properly set.

backend/models/dtos/__init__.py

@@ -33,20 +33,24 @@ def wrapper(*args, **kwargs):
             try:
                 dto = dto_class()
 
-                # Set attribute values from request body, query parameters, and path parameters
                 for attr in dto.__class__._fields:
-                    if request.is_json and attr in request.json:
-                        setattr(dto, attr, request.json[attr])
-                    elif attr in request.args:
-                        setattr(dto, attr, request.args.get(attr))
-                    elif attr in kwargs:
-                        setattr(dto, attr, kwargs[attr])
+                    # Get serialized name of attr if exists otherwise use attr name
+                    field = dto.__class__._fields[attr]
+                    attr_name = field.serialized_name if field.serialized_name else attr
+
+                    # Set attribute value from request body, query parameters, or path parameters
+                    if request.is_json and attr_name in request.json:
+                        setattr(dto, attr, request.json[attr_name])
+                    elif attr_name in request.args:
+                        setattr(dto, attr, request.args.get(attr_name))
+                    elif attr_name in kwargs:
+                        setattr(dto, attr, kwargs[attr_name])
 
                 #  Set authenticated user id if user_id is a field in the DTO
                 if "user_id" in dto.__class__._fields:
                     dto.user_id = token_auth.current_user()
 
-                # Get accepted languages from request header
+                # Get accepted language from request header
                 if "preferred_locale" in dto.__class__._fields:
                     dto.preferred_locale = request.environ.get(
                         "HTTP_ACCEPT_LANGUAGE", "en"