fix: improve error handling and add type checks in various providers and API

- Updated error handling in g4f/Provider/DDG.py to raise ResponseError instead of yield error strings
- Replaced yield statements with raises in g4f/Provider/DDG.py for HTTP and response errors
- Added response raising in g4f/Provider/DeepInfraChat.py for image upload responses
- Included model alias validation and error raising in g4f/Provider/hf/HuggingFaceMedia.py
- Corrected model alias dictionary key in g4f/Provider/hf_space/StabilityAI_SD35Large.py
- Ensured referrer parameter default value in g4f/Provider/PollinationsImage.py
- Removed duplicate imports and adjusted get_models method in g4f/Provider/har/__init__.py
- Modified g4f/gui/server/api.py to remove unused conversation parameter in _create_response_stream
- Fixed logic to handle single exception in g4f/providers/retry_provider.py
- Added missing import of JsonConversation in g4f/providers/retry_provider.py
- Corrected stream_read_files to replace extension in return string in g4f/tools/files.py

g4f/gui/server/backend_api.py

@@ -128,7 +128,6 @@ class Backend_Api(Api):
             return self.app.response_class(
                 self._create_response_stream(
                     kwargs,
-                    json_data.get("conversation_id"),
                     json_data.get("provider"),
                     json_data.get("download_media", True),
                 ),