exo data refactor

[bnb32]

#152 (comment)

[grantbuster]

Here's a start to what FWP should look like. We might want to further improve exo_steps.

    "exo_kwargs": {

"topography": {
        "exo_handler": "ExoTopo",
        "file_paths": ["/scratch/gbuster/sup3r/source_gcm_data/wind_solar_day_MRI-ESM2-0_ssp585_r1i1p1f1_gn_20150101-20151231.nc"],
        "source_file": "/scratch/gbuster/sup3r/source_gcm_data/nsrdb_clearsky.h5",
        "target": [23.2, -129],
        "shape": [26, 59],
        "s_enhancements": [1, 5, 5],
        "agg_factors": [625, 25, 1],
        "input_handler": "DataHandlerNCforCC",
        "exo_steps": [0, 1, 2]
},

"solar_zenith_angle": {
        "exo_handler": "ExoSZA",
        "file_paths": ["/scratch/gbuster/sup3r/source_gcm_data/wind_solar_day_MRI-ESM2-0_ssp585_r1i1p1f1_gn_20150101-20151231.nc"],
        "source_file": "/scratch/gbuster/sup3r/source_gcm_data/nsrdb_clearsky.h5",
        "target": [23.2, -129],
        "shape": [26, 59],
        "s_enhancements": [1],
        "agg_factors": [1],
        "input_handler": "DataHandlerNCforCC",
        "exo_steps": [3]
}
    },

[grantbuster]

https://github.com/NREL/rex/blob/main/rex/utilities/solar_position.py