Dask Worker profiles to be restricted by user groups [enhancement]

[danlester]

Description

Currently, all possible Dask profiles appear to be accessible to all users.

We should make it possible to restrict access to specified groups, as we do for JupyterLab profiles. This includes having a Keycloak group attribute to determine which groups have access, as well as the ability to specify in qhub-config.yaml.

Value/benefit

This allows security in resource management for the admin, as well as simplicity for end users.

[costrouc]

This is a feature worth having but low priority since we have not had anyone ask for this. Let us know if this issue is important to you!

[iameskild]

This feature is currently available for JupyterLab profiles and I think it would be worth looking into for Dask-Worker profiles as well.

Adding help wanted label.