Add/review crs for serap data

Add (or review for accuracy if it already exists) crs information to serap datasets, which likely have the same crs (but please check this):

• s3://mdmf/gdp/sambi_urb.zarr
• s3://mdmf/gdp/serap_slamm.zarr
• s3://mdmf/gdp/serap_urb.zarr

They have the following THREDDS catalog entries, if that is helpful to have:

• https://cida.usgs.gov/thredds/catalog.html?dataset=cida.usgs.gov/serap/sambi_urb
• https://cida.usgs.gov/thredds/catalog.html?dataset=cida.usgs.gov/serap/slamm
• https://cida.usgs.gov/thredds/catalog.html?dataset=cida.usgs.gov/serap/serap_urb