Expansion of the usgscsm_cam_test tool and documentation (#377)

* Flesh out the usgscsm_cam_test tool and minor touchups

* Adjust the test command

* Try to create a manual page for the new tool

* Fix link to subpage

* Expand the doc

Update usgscsm_cam_test.rst

Minor wording changes

More minor wording

More wording changes

Consistent style and other minor

Another wording fix

* Minor header file tune-up

* Use true and false instead of 0 and 1

* Add test to read model state

* Minor code touch up, and maybe the submodule error goes away

* Try to fix the json issue

* The json thing just would not let go