Refs #10223 Add instrument selection controls to Refl UI
Refs #10223 Load runs with respect to selected instrument
Refs #10223 Minor Refl UI tweaks
Refs #10223 Update unit tests to pass

The unit tests have not yet been thoroughly reviewed. They are due to be
heavily rewritten and documented to test the different use cases in a
thorough and easy to follow way.
Merge branch 'feature/10223_new_refl_ui_improvements' into develop