Change URIs of imported EDAM classes to ITO namespace

[matthias-samwald]

We disagree with some of the class structure of EDAM and are changing it. To honor EDAM policy, we need to change the URIs to our own namespace, and retain a mapping of each class to the original EDAM URI (e.g. via a rdfs:seeAlso datatype property value containing the original EDAM URI).