maptrim app conversion + gtests (#4201)

* Maptrim app to function conversion and gtests

* Reopen projTestCube to save DNs to cube

* Fixed keyword typo

* Adjusted automos test histograms to account for DNs

* Fixed automos standard deviation

* Removed template comment

* Removed old makefiles

* Converted member vars/funcs to static

* Tests that the app log is populated with a mapping group.