Update prefixes from hmas-int to hmas

The tests should pass if different prefixes resolve to the same namespace (anyone can use any prefix they like, resolving to the right namespace is what is tested).

Additionally, what should be updated are the namespaces:

https://purl.org/hmas/core# should be updated to https://purl.org/hmas/ e.g. https://purl.org/hmas/Signifier.
https://purl.org/hmas/interaction# should be updated to https://purl.org/hmas/ e.g. https://purl.org/hmas/ActionExecution.

danaivach / hmas-java

Update prefixes from hmas-int to hmas #4