Revert reverted histogram PR and handle conflicts. (#4004)

* Revert reverted histogram PR and handle conflicts

* Added changelog entry

* ERROR

* local stats fix

* Added new ImageHistogram class

* Actually added the ImageHistogram class

* Made shared variable protected so subclass can access it

* Used virtual functions and reverted Cube::histogram to return a Historgram

* Added back pipe to dev/null in makefile

* Fixes to some app and unit test in the hist PR

* More test fixes

* Final updates to programs and test data for new histogram calculations

* Split the rolls of imagehistogram and histogram

* Added and updated unit test truth data

* Added the ImageHistogram unittest file

* Resolved last comments on hist PR

Co-authored-by: Adam Paquette <acpaquette@usgs.gov>