Add mappings/equivalences to Expasy Enzyme categories

[johnbachman]

e.g., the MAP kinases are listed as entry 2.7.11.24 in the Expasy enzyme taxonomy, see https://enzyme.expasy.org/EC/2.7.11.24. Some reading systems produce groundings to this taxonomy.

[cthoyt]

Maybe we could make some concerted effort to update bio2bel-expasy since it already has code for downloading/parsing the ExPASy database. It needs some clean up but if it would be useful I'd put some more time into it