Documentation and other minor TODOs

[patrick-austin]

• Readme is empty
• No license file (other ICAT repos seem to use apache 2)
• scm missing from the pom.xml (when compared to e.g. authn.simple) - is this needed for deployment to the repo?
• Some descriptive/documenting fields missing from the pom (license, organization, distribution management)
• No CI/GHA
• icat.utils 4.17.1 is released, so we don't need to use the snapshot as a dependency
• One reference to authn.simple:

  authn.delegating/src/main/scripts/setup

  Line 5 in 652e786

  # authn.simple

• Quarkus tests could have a comment to explain that the same tests are run because it extends the "main" test class, but with the quarkus specific import/decorator