Jlorincz/common testing

[lajz]

TODO:

• Complete non-pytest testing helpers
• move cli testing to use common infrastructure
• figure out what assert statements should exist and where
• fix up constants and verbosity settings
• create better system for detecting tokamak
• create the option to overwrite constant with environment variables
• ability to run scripts from python, not pytest
• xfailures and xsuccesses

[gtrevisan]

in order to help us develop the parameter methods, we should use the xfail mark from pytest for methods that are known failures but should not prevent the whole workflow from succeeding.
https://docs.pytest.org/en/6.2.x/skipping.html#xfail-mark-test-functions-as-expected-to-fail

[gtrevisan]

thank you! are you able to push the appropriate known failures list for each machine so that the tests pass? also, there might be some tweaks to be done on my earlier tests.

[gtrevisan]

(1) as a final touch for now, please organize data in a more structured way, eg:

TEST_SHOTS = {
    "CMOD": <current CMOD_TEST_SHOTS>,
    "D3D: <current D3D_TEST_SHOTS>,
}

etc, it should be a lot easier to then read them up depending on the tokamak parameter.

(2) then, please remove the shot-by-shot info from the expected failures.

(3) finally, please fix the _fast logic which is currently flipped.