Camstats normalization and test refactor (#3696)

* Abstracted campt app.

* Revert "Merge branch 'campt' of https://github.com/kaitlyndlee/ISIS3

 into dev"

This reverts commit 521dd44a6831b488052aa0e21e65ca3c5f40f7f1, reversing
changes made to 2874acf6.

* normalized camstats, added functional tests

* removed old test makefile

* added docstring

Co-authored-by: Kaitlyn Lee <kdl222@nau.edu>