Add/review crs for macav2 data

Add (or review for accuracy if it already exists) crs information to macav2 datasets, which likely have the same crs (but please check this):

• s3://mdmf/gdp/macav2_future_daily.zarr
• s3://mdmf/gdp/macav2_future_monthly.zarr
• s3://mdmf/gdp/macav2_historical_daily.zarr
• s3://mdmf/gdp/macav2_historical_monthly.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/macav2metdata_daily_future
• https://cida.usgs.gov/thredds/catalog.html?dataset=cida.usgs.gov/macav2metdata_monthly_future
• https://cida.usgs.gov/thredds/catalog.html?dataset=cida.usgs.gov/macav2metdata_daily_historical
• https://cida.usgs.gov/thredds/catalog.html?dataset=cida.usgs.gov/macav2metdata_monthly_historical