Add optional query to cacher to limit nodes included in search

[zi0r]

Description

In large environments, a query of all ssh host keys may be too large to insert into a single databag post. This allows you to limit your search criteria that is used by a cacher.

Issues Resolved

I created a PR instead of an issue.

Check List

• All tests pass. See https://github.com/chef-cookbooks/community_cookbook_documentation/blob/master/TESTING.MD
• New functionality includes testing.
• New functionality has been documented in the README if applicable
• All commits have been signed for the Developer Certificate of Origin. See https://github.com/chef-cookbooks/community_cookbook_documentation/blob/master/CONTRIBUTING.MD