converts terms/index js_block into js_bundle

test plan:
* regression test term index

Change-Id: I9e37b1676beb19a3e49efde78d6b1b051f5b6bdf
Reviewed-on: https://gerrit.instructure.com/29099
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jon Jensen <jon@instructure.com>
QA-Review: Steven Shepherd <sshepherd@instructure.com>
Product-Review: Landon Wilkins <lwilkins@instructure.com>