Add driver script to convert GSI bias coefficient files for UFO

[CoryMartin-NOAA]

Addresses part of #7

This adds a new ush script, run_satbias_conv.py that will loop through specified cycles and convert GSI bias files (eg. gdas.t00z.abias and gdas.t00z.abias_pc) to files readable by UFO.

Usage:
./run_satbias_conv.py --config input.yaml

This input YAML file should contain the following:

start time: 2021-12-20T18:00:00Z
end time: 2021-12-21T18:00:00Z
assim_freq: 6
dump: gdas
gsi_bc_root: /path/to/gsi/rotdirs
ufo_bc_root: /path/to/output/toplevel
work_root: /path/to/toplevel/work
satbias2ioda: /path/to/build/bin/satbias2ioda.x

All three directories should/will have the structure within them:
{dump}.YYYYMMDD/HH/atmos

Still to come: the associated unit test to convert a sample GSI file, and the R2D2 test to place the converted files in R2D2

[guillaumevernieres]

Don't know about the science, but the code look 👍

[emcbot]

Automated Pull Request Testing Results:
Machine: orion

Start: Fri Apr  1 15:15:14 CDT 2022 on Orion-login-1.HPC.MsState.Edu
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Build:                                 *SUCCESS*
Build: Completed at Fri Apr  1 15:58:40 CDT 2022
---------------------------------------------------
Tests:                                 *SUCCESS*
Tests: Completed at Fri Apr  1 15:59:23 CDT 2022
Tests: 100% tests passed, 0 tests failed out of 7

[emcbot]

Automated Pull Request Testing Results:
Machine: hera

Start: Fri Apr  1 20:15:16 UTC 2022 on hfe10
---------------------------------------------------
Build:                                 *SUCCESS*
Build: Completed at Fri Apr  1 21:07:20 UTC 2022
---------------------------------------------------
Tests:                                 *SUCCESS*
Tests: Completed at Fri Apr  1 21:07:34 UTC 2022
Tests: 100% tests passed, 0 tests failed out of 7