feat: enable embedded superset and charts

[Ian2012]

Description

This PR enables embedded Superset and charts feature flags.

This prepares the terrain for Instructor dashboard integration via Superset iframes.

https://medium.com/@khushbu.adav/embedding-superset-dashboards-in-your-react-application-7f282e3dbd88

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[itsjeyd]

Thanks for these changes @Ian2012! Are they ready for review?

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