Add a simple wrapper for `nearlyEqlDbl`
Add a simple wrapper for `nearlyEqlDbl`

This wrapper performs the check, runs the GTest assertion, and provides
some nice output on test failure

evaneschneider/cholla,cholla-hydro/cholla,evaneschneider/cholla,cholla-hydro/cholla,evaneschneider/cholla,cholla-hydro/cholla,evaneschneider/cholla,cholla-hydro/cholla