Revert "fix mathml render"
Revert "fix mathml render"

fixes MAT-1069

This reverts commit 43511c5542f6dcc84bb38ca36df01ce9a7d241da.

Reason for revert: This commit hides equation images globally, which
means equations won't appear in places where the mathjax typesetting
doesn't happen (e.g. Classic Quizzes)

Change-Id: I3f2728cb07fbbc216812fc6c8e0714f58ea708c3
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/302761
Reviewed-by: Deyvison Penha <ff32ea30c587f07b9af366bcbbe18a4541309209@instructure.com>
QA-Review: Jon Scheiding <9af6aa5061dd5eef0e85122953253a66930fcf3e@instructure.com>
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
Product-Review: Jon Scheiding <9af6aa5061dd5eef0e85122953253a66930fcf3e@instructure.com>

sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms