create public courses report

closes CNVS-13328

test plan
 - set a course to public
 - run report, it should include the public courses

Change-Id: Ia3ef9ed62604039998bd90ef06337157dc0c5acb
Reviewed-on: https://gerrit.instructure.com/35557
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
QA-Review: August Thornton <august@instructure.com>
Product-Review: Rob Orton <rob@instructure.com>