[Do not merge] Spr 939 test runner improvement 2

[ella-springtail]

test

[linear]

SPR-939 Test runner: fixup runtime options

Right now you can run the test runner using the following options:
-a : run everything all test cases; used by nightly

<test_case_name> : run that test case and its overlays

-o : overlay and all test cases using that overlay — I believe — (may be combined with test_case_name)

: run default test cases and their overlays

Right now:

Running with no default runs the default set and EVERYTHING in the overlays even if the overlay specifies different test_cases.

The only way to have a test that depends on an overlay is to set a flag in the overlay section, but this test case can't be run in the defaults since it won't apply the overlay.

Need to clean it up; the code in test_runner.py is convoluted.
The -a option should run everything will all overlays
No options should run the default set and the overlays for THAT default set ONLY

There should be a way to specify a test_case requires an overlay.
The -o option should continue to work when specified either with a specific test_case or no test_case.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[ella-springtail]

This PR was just for testing