Implement the to_dask() function

[edwardchalstrey1]

I'm attempting to use the intake_stac.StacCollection class in a similar way to other non-stac intake catalogs, but I noticed it doesn't yet have a to_dask() function implemented:

[scottyhq]

@edwardchalstrey1 this library only implements .to_dask() for Items not Collections.

You are trying to load the entire sentinel-s2-l2a collection into a single dask-backed Xarray dataset, which would require some sophisticated alignment and possibly reprojection.

Development efforts down that road stalled in #75, but if that workflow is what you are interested in you might try https://github.com/gjoseph92/stackstac or https://github.com/opendatacube/odc-stac

[edwardchalstrey1]

Great, thanks @scottyhq :)