pstree.py has broken types and pid handling

[atcuno]

This is code is confusing as it expects a two element tuple even though the default is None:

https://github.com/volatilityfoundation/volatility3/blob/develop/volatility3/framework/plugins/windows/pstree.py#L64

I was trying to understand pid but its typing in the function parameters shows:

pid: objects.Pointer,

But then self._processes is declared as:

self._processes: Dict[int, Tuple[interfaces.objects.ObjectInterface, int]] = {}

And it definitely seems to store ints:

https://github.com/volatilityfoundation/volatility3/blob/develop/volatility3/framework/plugins/windows/pstree.py#L100

@superponible can you take a look at this one?