kyua: Do not count skipped as passed in test cmd

It changes output of 'kyua test' CLI command only. Hence, other outputs
like junit are kept intact for CI and other use cases. It's meant to
improve UX of attended use cases.

The issue is that the following can be tricky to interpret:

222/222 passed (0 failed)

It can be read as all tests are passed, but it might be a summary line
of all tests skipped due to some requirement is not met.

It's reworked to easily distinguish such cases:

222/222 passed (0 broken, 0 failed, 0 skipped)
0/222 passed (0 broken, 0 failed, 222 skipped)

The overall formula is:

<actually passed>/<total> (<details about not actually passed ones>)

Suggested by: kp
Reviewed by: ngie, markj
Approved by: markj (mentor)
Differential Revision: https://reviews.freebsd.org/D46653