kunit: tool: Parse and print the reason tests are skipped

kunit: tool: Parse and print the reason tests are skipped

When a KUnit test (or other KTAP test) is skipped, a "skip reason" can be
provided. kunit.py has never done anything with this, ignoring anything
included in the KTAP output after the 'SKIP' directive.

Since we have it, and it's used, print it in a nice friendly yellow in
parentheses after a skipped test's name.

(And, by parsing it, it can be included in the JUnit results as well.)

Link: https://lore.kernel.org/r/20260606013827.240790-1-david@davidgow.net
Signed-off-by: David Gow <david@davidgow.net>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>