DrugChemical conflation defaults to the numerically smallest identifier, which doesn't always work

[gaurav]

We should replace this with someone smarter -- for example, we could pick the identifier with the shortest label to try to pick the main element and not a salt form.

Babel/src/createcompendia/drugchemical.py

Lines 466 to 468 in d0502c6

	# Sort this final set of CURIEs from the numerically smallest CURIE suffix to the largest, with
	# non-numerical CURIE suffixes sorted to the end.
	final_conflation_id_list.extend(list(sorted(prefixes_to_add, key=sort_by_curie_suffix)))

Failure cases:

• imatinib should be CHEBI:45783 rather than CHEBI:31690