feature: amp-106 further tidy project

* Switch to using flyway in int tests
* Switch to using example database table and repository to line up with service and controller which were already example
* Switch h2 database to TestContainers

Author: coling01

.github/workflows/ci-build-publish.yml

@@ -50,7 +50,6 @@ jobs:
     outputs:
       repo_name: ${{ steps.repo_vars.outputs.repo_name }}
       artefact_name: ${{ steps.repo_vars.outputs.artefact_name }}
-    env:
     steps:
       - name: Checkout source code
         uses: actions/checkout@v6