removes js_blocks in gradebooks/grade_summary

test plan:
* gradebook regressions

Change-Id: I6706fa542dcf3c00efcc061fdc14f574960bc7dc
Reviewed-on: https://gerrit.instructure.com/29144
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Amber Taniuchi <amber@instructure.com>
Reviewed-by: Jon Jensen <jon@instructure.com>
Product-Review: Landon Wilkins <lwilkins@instructure.com>