Show assignment in enhanced view from student grades page
Show assignment in enhanced view from student grades page

closes EVAL-2017
flag=assignments_2_student

Test plan:
Have a student with an assignment and go to the student grades
page:
1. With FF on, click on the assignment title and make sure it
shows the assignment in the improved assignment submission flow
2. With the FF off, click on the assignment title and see that
it shows the assignment in the old view

Change-Id: I8dd4fa90d2fc52329f68ecc5cd7d5af3525223a3
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/275419
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
Reviewed-by: Kai Bjorkman <4693b3d9e71784d629732770ab5e83ed8fbdb83e@instructure.com>
Reviewed-by: Aaron Shafovaloff <d0ee6b99167c663aba7bc3efd806fe8d6cad437b@instructure.com>
QA-Review: Aaron Shafovaloff <d0ee6b99167c663aba7bc3efd806fe8d6cad437b@instructure.com>
Product-Review: Jody Sailor

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