- Standardize play/tasks naming
- Move install checks to separate playbook with checkpointing
- Correct 'docker_storage' tags

Add playbook to run adhoc health checks or list existing checks

This is useful on its own, and also aids in developing/testing new
checks that are not part of any playbook.

Since the intent when running this playbook is to execute checks, opt
for a less verbose explanation on the error summary.

- The referenced issue was closed, seems like a wontfix. Just use the
old syntax and make no noise about it.
- Remove inconsistent use of tags: if tags are passed in the command
line, there is no point in evaluating groups if the checks won't be run
anyway.
- Remove temporal comment, easy to get out of sync.

openshift_health_checker requires openshift_version, and that has been
updated to require group evaluation.
Update check playbooks and integration tests to do group eval.