fix: copy the whole message content when doing normalization (#818)

When using tools like openiterpreter, messages come with extra keys
apart from content and role, like "tool_calls". With this normalization
they were stripped and the tool was broken

Closes: #812

Author: yrobla

src/codegate/providers/normalizer/base.py

@@ -23,9 +23,8 @@ def _normalize_content_messages(self, data: Dict) -> Dict:
         messages = normalized_data["messages"]
         converted_messages = []
         for msg in messages:
-            role = msg.get("role", "")
+            new_msg = msg.copy()
             content = msg.get("content", "")
-            new_msg = {"role": role, "content": content}
             if isinstance(content, list):
                 # Convert list format to string
                 content_parts = []