Reconcile wrf_load() and wrf_loadTimeSeries()

[tabrasel]

• wrf_load(): loads a snapshot of a single forecast hour from a WRF model run. It returns a RasterBrick with a RasterLayer for each requested variable from that point in time.
• wrf_loadTimeSeries(): loads multiple forecast hours from a WRF model run. It returns a RasterBrick with a separate RasterLayer (single variable) for each requested hour.

Maybe we could combine the two functions into wrf_load() and have it return a list of RasterBricks. Each brick would represent a forecast hour, and each RasterLayer in a brick would store a variable. Or, if we think it's better to keep them separate, wrf_load() should at least have a more descriptive name.

One downside of the list approach is that if a user asks for just one variable over multiple hours, then a list of single-layered RasterBricks will be returned which is a bit space inefficient.

[jonathancallahan]

Downloading enough data to create a timeseries is not feasible so all timeseries functionality is on permanent hold.