Tables don't reload after switching to another Instructor dashboard tab and switching back

[bryanlandia]

There isn't any code to re-display the Instructor dashboard table of assessments except when returning from an assessment view or a staff grading view.

To reproduce:

1. navigate to the Instructor dashboard on a course that has ORAs
2. see the tables of assessments
3. switch to 'certificates', 'course data' or another tab on the Instructor dashboard
4. switch back to the ORA tab

expected: the assessment tables are visible actual: the text "Please wait" appears, but no tables