Probable typing error in "new_struct" function

Hi,

I think there is an error with the typing of function "new_struct" on this line:

https://github.com/FreeOpcUa/opcua-asyncio/blob/5b1091795dc7745efb94acd94381db17274779e8/asyncua/common/structures104.py#L61

I suspect the correct code would be:

```python
    name: Union[ua.QualifiedName, str],
``` 

