Add add increment application with variable change capability

[DavidNew-NOAA]

This PR creates two FV3-JEDI applications, both are versions of the general JEDI AddIncrement application. Both applications use the same header file, which adds the option to perform a variable change after adding the increment. This is useful if, for example, the background state contains ps and delp, but the increment only contains delp. ps is derivable from delp, so the variable change allows you to recalculate ps based on the new delp after increment addition.

One application is a conventional JEDI application while the other is an ensemble application (used in Global Workflow for ensemble recentering.)

[delippi]

@DavidNew-NOAA thank you so much for already moving this code here! I'm still learning how to use the version of this code from GDASApp, but I suspect this will be what we want to use going forward. I hope RDASApp will soon add this repo as a submodule.

[DavidNew-NOAA]

CI actually failed I just noticed. Can't find

#include "fv3jedi/Utilities/Traits.h"

I need to look into this tomorrow