translate course report headers

refs CNVS-3134

test plan
 - course report examples and report headers
   should be translated

Change-Id: I1ed6e93886c281c0f8635aca63171af8966bc58c
Reviewed-on: https://gerrit.instructure.com/34577
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>