cmd: Update subcommands to support fails explanation mode

This change updates the test command to use the fail explanation mode
by default. Since the test framework expects test rules to be
defined/true failure events are usually what is required to debug test
failures (e.g., some assertion in the test rule will Fail and that
will _likely_ be based on some failure in the policy under test.)
Hopefully this makes the test output a bit less verbose and more readable.

Signed-off-by: Torin Sandall <torinsandall@gmail.com>