Task 1-1: Encode NWM Gridded Output as Zarr

[lewfish]

Under this task, Azavea will evaluate the potential of Zarr, an alternative cloud native format for chunked data, for its ability to store and query gridded NWM outputs more rapidly and efficiently than current methods.

[lewfish]

Relevant notebook: https://github.com/azavea/noaa-hydro-data/blob/master/notebooks/save_nwm_sample.ipynb