Automated tests

[dieggsy]

It would be great if github actions could be set up to test at the very least building CLSQL on supported CL versions. I've worked with Gitlab CI and not github actions, but I'm sure I could figure it out.

[dieggsy]

It should be possible to run tests on the DB types themselves using podman or docker where needed. There appear to be containers for most of the major RDBMS.