Check that numerical component of an EDAM concept ID is unique

[joncison]

The numerical component of an EDAM concept ID is duplicated in some other concept ID.

[joncison]

done, see https://github.com/edamontology/edamverify/blob/master/queries/iDNumericalDuplication.ipynb

would benefit from a review at some stage @albangaignard @hmenager

an interesting footnote on this one (reflected in the code) is that EDAM subsets - being defined as XML attributes in the RDF/XML - are not amenable e.g. to FILTER SPARQL queries, which only work on XML element values. It took me a while to realise this! Had it been otherwise, more of the logic could have been put in the SPARQL query. Correct me if I'm wrong here, Alban!