(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.
Fix this to not use distmoduledir and uncomment.