Instructor Dashboard: Update data download section, grade reports in student admin section and certificate reports.

[eemaanamir]

We need to add changes for all of the following in instructor dashboard:

1. Grade reports in the student admin section:
   Commit: 879d64e
2. Add permission to course staff to access data download section + Changes in the certificate report + Grade report simplification:
   PR: Relocate and simplify grade and certificates instructor reports #439

PRs:

• feat: update intructor dashboard reports and permissions #572
• feat: added utils for reports in student admin openedx-wikilearn-features#11
• chore: added styles for reports table in instructor dash tutor-indigo-wikilearn#20