Support python bitwise operators for residue selectors in PyRosetta

[klimaj]

This PR adds support for use of python bitwise operators for ResidueSelector objects in PyRosetta. Residue selectors are now able to be combined by the following PyRosetta-to-python operator symbol conversions:

• AndResidueSelector --> &
• OrResidueSelector --> |
• NotResidueSelector --> ~
• Exclusive OrResidueSelector --> ^ (there isn't technically an exclusive OrResidueSelector in PyRosetta, but it could be implemented with the Logic residue selector in XML. This is intended to be equivalent to a XOR operation or the symmetric difference in set theory)
• In-place AndResidueSelector --> &=
• In-place OrResidueSelector --> |=
• In-place exclusive OrResidueSelector --> ^=

Only python bitwise operators are affected, while python boolean operators and, or and not are unaffected when implemented with ResidueSelector objects.

Also thanks to @everyday847 for the original idea to override the __and__ method of residue selector objects.

[klimaj]

Thanks @lyskov, that's a good point -- I've now moved the unit test to src/test/T121_core.ResidueSelector.py and it's passing on the benchmark server!

[ajasja]

This is excellent, thanks @klimaj ! (Sorry for seeing this so late.) Too bad we can't overload the logical and, or etc, but there are good reasons why not https://peps.python.org/pep-0335/ :)