Add canonical and tuple identifiers to output

We currently only provide concept identifiers as URLs (e.g. [NCIt C799](https://ncit.nci.nih.gov/ncitbrowser/pages/concept_details.jsf?dictionary=NCI+Thesaurus&code=C799)). We should also provide concept identifiers as tuples (i.e. `(NCIt, C799)`) and as a canonical URL (`http://ncicb.nci.nih.gov/xml/owl/EVS/Thesaurus.owl#C799`) in order to facilitate mapping to other resources. We could also include the permissible value public identifiers (HOT-Ecosystem/cadsr-on-fhir#4) for elements that don't map to an NCIt concept.

Trace the existing concept-identifier output and NCIt mapping logic, starting from the code that emits the current NCIt browser URL. Update the output to include the `(NCIt, C799)` tuple and canonical URL forms, then verify the generated CSV output against the examples in the issue; investigate permissible value public identifiers separately if that mapping is available.

Written by the indexing model from the issue text.