Initial application + testing refactor for cnetbin2pvl (#3693)

* Initial application/testing refactor of cnetbin2pvl

* Removed makefile for old test.

* Adjusted spacing to better comply with isis3 internal standard.

* Removed default cnetbin2pvl testing makefile

* Addressed PR comments / reviews.

Removed old comment
Removed unnecessary cnet write
Added default null pointer for progress parameter.

* Removed extra whitespace