ENH: TIMED SABER/SEE netCDF support

[jklenzing]

Is your feature request related to a problem? Please describe.
netCDF files are archived on CDAWeb: https://cdaweb.gsfc.nasa.gov/pub/data/timed/saber/level2a_v2_07_netCDF/

Describe the solution you'd like
It might be easier to incorporate these rather than cdf. Code would be similar to ICON implementation.

Describe alternatives you've considered
Fix the cdf / xarray integration #92

Additional context
Needs unzipping capabilty: #103

[jklenzing]

A new version is out, with a file rename to boot. May want to accelerate this task.

[jklenzing]

Note that netCDF files use a 3-digit day of year rather than month and day. This requires a change to the remote file download routine, since only month and day are supported. Could use code from pysatCDAAC. Or could accelerate development of pysat/pysat#1012 to create a working download routine for both packages in the core code.

[jklenzing]

3-digit day solved by TIMED/GUVI integration.

cdflib/xarray support having trouble with multi-day files (ie, SABER. found while working #136)

[jklenzing]

#160 may replace this issue by fixing the xarray support using cdflib

[jklenzing]

Noting an issue for TIMED SABER: there is a 2d variable called 'time' (since data is swept over altitude), which we currently rename as 'tp_time'. This functionality is not currently present in the cor pysat netcdf load routine, prompting errors.

[jklenzing]

Both SABER and SEE have issues with the current implementation of load_netcdf from pysat. SEE does not have a datetime index in the file, only date and time (ut sec since midnight). Since the cdflib has a working solution now, we should probably either close this issue or bump it down the line until new capabilities are added to pysat.