make parse optional

[meeuw]

I'd like to python-hid-parser with some descriptors that can't be parsed by the default parser (similar to #10).

With these changes ReportDescriptor.print() is usable though and allows me to extend ReportDescriptor and use self._iterate_raw.

[FFY00]

Things will break when using the rest of the functionality when we don't parse, we should have checks for that. However, I think it would be better if instead of allowing the user to disable the parsing, to just delay the parsing until needed.

For that, we should probably turn

https://github.com/usb-tools/python-hid-parser/blob/main/hid_parser/__init__.py#L603-L605

into a NamedTuple

class _Pools(NamedTuple):
    input = _ITEM_POOL
    output = _ITEM_POOL
    feature = _ITEM_POOL

And then make it a property, where we trigger the parsing when accessed

@property
def _pools(self) -> _Pools:
    if not self._parsed:
        self.__pools = _Pools({}, {}, {})
        self._parse()
        self._parsed = True
    return self.__pools

[meeuw]

After some hacking I found out that I actually need some information from _parse and I shouldn't re-implement it.

I'll try to create another PR to see if I can fix the parser or at least let it fail gracefully.