EvalModuleCallArguments is now a method on nodeModuleVariable, it's only
caller, and the other functions have been replaces with straight through
code (or in the case of evalVariableValidations, a standalone function).
I was unable to add tests for nodeModuleVariable.Execute, which requires
fixtures that aren't part of the MockEvalContext (a scope.evalContext is
one); it's not ideal but that function should be well covered by the
context tests so I chose to leave it as-is.
Finally, I removed the unused function hclTypeName. Deleting code is
fun!
