RFC: Adds test_broken and test_skip macros

[morris25]

test_broken and test_skip can be used to designate tests that should pass but don't. In an attempt to be noticed by testers they produce a Brokenresult. test_skip will simply skip over testing, and test_broken will raise an error to alert the user if the test unexpectedly succeeds.

This pull request is a continuation of #15832.

[tkelman]

Other than the test report always displaying the count of how many there were, how is "skip" materially any different than commenting out a test?

[omus]

I think the current version @test_skip is materially the same as commenting out a test. The main advantage is that the report reminds developers that there is an unfinished test case to deal with.

[wildart]

How hard it would be implement skipping of testsets with appropriate reporting?

[tkelman]

see #17038

[StefanKarpinski]

thanks, @tkelman