openshift_checks: enable providing file outputs

Some refactoring of checks and the action plugin to enable writing files
locally about the check operation and results, if the user wants them.
This is aimed at enabling persistent and machine-readable results from
recurring runs of health checks.

Now, rather than trying to build a result hash to return from running
each check, checks can just register what they need to as they're going
along, and the action plugin processes state when the check is done.
Checks can register failures, notes about what they saw, and arbitrary
files to be saved into a directory structure where the user specifies.
If no directory is specified, no files are written.

At this time checks can still return a result hash, but that will likely
be refactored away in the next iteration.

Multiple failures can be registered without halting check execution.
Throwing an exception or returning a hash with "failed" is registered as
a failure.

execute_module now does a little more with the results. Results are
automatically included in notes and written individually as files.
"changed" results are propagated. Some json results are decoded.

A few of the checks were enhanced to use these features; all get some of
the features for free.

0 files changed, 0 insertions, 0 deletions