AIP-74: Support grouping Asset by group attribute

[Lee-W]

Description

Use case/motivation

https://cwiki.apache.org/confluence/display/AIRFLOW/AIP-74+Introducing+Data+Assets

Related issues

No response

Are you willing to submit a PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[Lee-W]

This will be picked up once most of the backend work of AIP-75 is done

[Lee-W]

Hi @bbovenzi @pierrejeambrun , we've wrapped up most of the APIs needed. What would be the best way for us to push the UI part forward? Thanks!