Nanopubs that don't have the Trusty code in their graph URIs should be rejected

[tkuhn]

Currently Nanopub Registry accepts such nanopubs with graph URIs that have a different hash: https://registry.petapico.org/np/RA3QeEArKrJhMi5hGQJwjizvDEPKnaM2wME9iuKItk_nE

The graph URIs need always be extensions of the base nanopub URI (so we can load them into triple store with guarantee for no graph overlap).

Maybe this should also be changed in nanopub-java, i.e. not recognizing such nanopubs as having a valid signature.

[ashleycaselli]

This change in nanopub-java should fix the issue. That prevents the NanopubLoader from loading the nanopublication when not trusty or the graph URIs are not an extension (start with) the base URI.

For testing purposes, I added https://registry.petapico.org/np/RA3QeEArKrJhMi5hGQJwjizvDEPKnaM2wME9iuKItk_nE (as invalid/trusty/trusty2.trig) to the nanopub-testsuite project.