MAR-218: Switch to using fully-qualified collection names for all tasks:

- Ensures there is no ambiguity when invoking a module.

MAR-218: Quote all octal values in YAML files:

- Fixes linting errors, and ensures there is no ambiguity in case of
YAML specification changes.

MAR-129: Updated backup role for new Ansible and Molecule:

- Fixed linting errors.
- Include top-level linting configuration in tests.
- Moved variables from test playbook into group_vars.
- Updated how the hosts are referenced in tests.

MAR-114: Updated task syntax for backup roles:

- Updated backup, backup_client, and backup_server.
- Added and removed quoting where it makes sense.
- Switched to using expanded syntax (instead of one-liners).
- Updated ordering of arguments in task definitions.

MAR-109: Minor fixes to backup role:

- Fixed mode parameters used in the role to include leading zero.