Add support for Mars Express HRSC SRC instrument (#3826)

* Add support for MacOS 10.14, needed for make base tests

* Add support for MEX SRC instrument

* Fixs found by PR review

* Fixed PR issues

* Tweaking translation

* Added exposure duration

* Adding in the SRC model

* Now with lat/lon, and test updates

* Adding Mex SRC Camera unitest

* Fix spelling in application docs.

Co-authored-by: Kristin <kberry@usgs.gov>