Add 'content' to freeradius::module, and fix status check

Allow for 'content' to be passed into freeradius::config and freeradius::cert

Rename the Service[radiusd] resource to Service[$fr_service].

This allows a user to use templates for their FreeRADIUS configuration
files rather than static files.

This can lead to private keys being exposed in logs when Puppet runs.

This allows the user to pass in raw content rather than just
a direct file resource. Great for use cases where people don't
store private keys in raw files in their repo, but use some alternative
method to get them.

This fixes unit tests on non-CentOS hosts where the service
name is freeradius instead of radiusd.