fix stream 模式下 raw tool calling 解析报错

[007gzs]

以下返回场景解析 `FunctionCall(name="", arguments=None)` 报错

Choice(delta=ChoiceDelta(content='', function_call=None, refusal=None, role='assistant', tool_calls=None), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=None, reasoning_content='好的'), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=None, reasoning_content='。。。\n'), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content='\n\n', function_call=None, refusal=None, role=None, tool_calls=None), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id='chatcmpl-tool-00dbf3e50b324db49fa8dd4a3bebe9c1', function=ChoiceDeltaToolCallFunction(arguments=None, name='漏洞信息'), type='function')]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='{"vul_id": "', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='CVE', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='-', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='2', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='0', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='2', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='2', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='-', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='2', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='5', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='5', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='1', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='7', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content=None, function_call=None, refusal=None, role=None, tool_calls=[ChoiceDeltaToolCall(index=0, id=None, function=ChoiceDeltaToolCallFunction(arguments='"}', name=None), type=None)]), finish_reason=None, index=0, logprobs=None)
Choice(delta=ChoiceDelta(content='', function_call=None, refusal=None, role=None, tool_calls=None), finish_reason='tool_calls', index=0, logprobs=None, stop_reason=None)