Improve CI tests

[RasmusSkytte]

Intent

Fixes #62
Fixes #78

Approach

For diseasystore we have been restructuring the workflows.
These workflows are available on https://github.com/ssi-dk/AEF-DDF/

This PR implements these workflows which have improved triggering conditions (fixes #62) and
separated test by DB backend (including SQL sever - fixes #78)

This requires some changes to setup.R and the test now draw their connections from get_test_conns()

A few tests had to be adjusted / removed in this new testing context

Known issues

This PR uses workflows from AEF-DDF that are not yet merged into main

• Improve test workflows with DB back ends AEF-DDF#7
  Once merged, this PR should change the source of the workflows to main on AEF-DDF

This PR is based on rc-v0.3 which is not yet merged into main

• Release SCDB 0.3 #79
  Once merged, this PR should be rebased to main

Checklist

• The PR passes all local unit tests
• I have documented any new features introduced
• If the PR adds a new feature, please add an entry in NEWS.md
• A reviewer is assigned to this PR

[marcusmunch]

Well, that was a mouthful—especially 0d43c2d.

I suppose that you intended to keep every commit as "complete" as possible, which in turn made the git diff quite hard to grasp. For the future, consider separating the commit into (for lack of better words) functional and syntactical changes in order to better reveal any actual changes to test functionality.