GitHub actions for build and test

[rukmal]

Create GitHub workflows to build and test the Ballerina project. Must be able to run locally with act, and on GitHub runners. Covers the complete set of workflows that will be run in a pull request.

• Build ballerina project
• db docker container
  • local build
  • push to registry
• Run ballerina tests

[rukmal]

Note that with act, some dependencies will be installed and run locally, as opposed to using GitHub's service construct for actions. See this comment for details.

[rukmal]

To change the git context in the docker build action, we must use the buildx builder. See: https://github.com/docker/build-push-action/#git-context

[rukmal]

docker buildx must be aliased to docker build for both pipelines to work on GitHub and locally. See: https://github.com/docker/setup-buildx-action#install-by-default

[rukmal]

Action fails at service container initialization stage with the error:

  /usr/bin/docker --config /home/runner/work/_temp/.docker_35d59d99-2883-4636-9d87-87ae74458d1a pull ghcr.io/Avinya-Foundation/global-data-db:main
  invalid reference format: repository name must be lowercase
  Error: Docker pull failed with exit code 1

This is due to Avinya-Foundation having capital letters. This is the fix: https://github.com/orgs/community/discussions/27086#discussioncomment-3254548