CAD score computation requires residue numbers in model and reference
to match. This raises an error in the Scorer object otherwise.
Catch this early on and raise an error specific to compare-structures
action with instructions on how to get rid of it.

Mainly for reporting in the compare-structures action
residues are reported as strings in format:
<cname>.<rnum>.<ins_code>, atoms are reported as
<cname>.<rnum>.<ins_code>.<aname>. This changes behaviour of
compare-structures and ost.mol.alg.stereochemistry
(ToJSON functions of violation info objects for the latter).

A global chain mapping can now be enabled with --global-chain-mapping as
a complement to the existing local chain mapping. This can be evaluated
for the scoring paper.

This makes the ligand scoring script more independent of an up-to-date
compound library, which is a strong requirement of Molck.
This was a problem for the April 2023 Modeling Championship where the
script was run with an out of date library and the element of an atom of
the ligand was silently changed, preventing the symmetry correction to
find isomorphisms and resulting in the absence of scores.

This may be necessary in case SDF ligands have the same chain/residue
number, which can happen with some input.

This should clarify what the binding site.

- Tell the user that biounit indices are 0-based
- More info in output on what chains are actually processed

This code is considered deprecated as of release 2.4.0. The new lDDT
implementation has already been integrated into
qsscoring.py/compare-structures. I prefer to leave this completely legacy.

same behaviour as old compare-structures

Before the program wrote the traceback into the output json but
exited silently. Now we re-raise upon writing the output.

commited for further review, currently co-exists with compare-structures