STAC catalog(s) for cloud holdings

[jbusecke]

At the recent ESGF meeting @rhysrevans3 helped me hack together a STAC catalog for the zarr data.

I propose we organize some time to hack on this in the near future. As a high level goal I propose a single STAC endpoint that makes both zarrs and netcdf data searchable. On the user facing level this would be a prototype for the new ESGF infrastructure (if virtualized zarrs are offered next to netcdfs in the catalog as 'equal' options next to netcdf files)!

My proposed milestones:

• Local prototype STAC catalog for each holding separately
• Discuss a way to merge and update the catalog with upcoming ingestions
• Stand up an API endpoint in the cloud and report back to users and ESGF

cc @aradhakrishnanGFDL @philipkershaw (please tag other folks here too)