(PUP-3248) Fix PMT tests for directory environment

The beaker host['distmoduledir'] variable is not meaningful if the
host is using directory environments (e.g. 'production').

This commit updates the helper methods for validating that a module
is (or is not) installed on the host by iterating over the
modulepath if a specific modulepath is not provided.

The calls to these helper methods have been updated for the change
in parameter ordering in the helper methods.
Right, but modulepath is a property of the environment.  Really all I'm saying is that it's clearer to obtain settings from puppet by using the `puppet config` tool and specifying environment and section as needed.  A `puppet agent --configprint modulepath` is the equivalent of saying `puppet config print --section agent modulepath`  And moving forward, modulepath is deprecated in a puppet.conf section.  Instead you really need to be asking `puppet config print modulepath --environment <something>`