Make searching for a compound using InChI easier
Currently, it can be done using the ccache:
from equilibrator_api import ccache
cpd = ccache.get_compound_from_registry("inchi_key", "WQZGKKKJIJFFOK-GASJEMHNSA-N")
However, we should also add an option to provide a full InChI, and perhaps also expose this interface directly through the ComponentContribution class.