LGETKF: add function to tune horizontal localization for each observer

[metdyn]

Description

This PR adds a mechanism to customize horizontal localization (e.g., Gaspari-Cohn) for obs in LGETKF.

• add a directory /jedi/interfaces/geos_atmosphere/observations/localization
• each yaml in that directory is used to update localization for the corresponding observer

Dependencies

Impact

[metdyn]

Offline for improvement

[Dooruk]

A quick question, did we confirm having localization in observation YAMLs break the Variational applications?

[metdyn]

A quick question, did we confirm having localization in observation YAMLs break the Variational applications?
@Dooruk, the added directory jedi/interfaces/geos_atmosphere/observations/localization is used by local ensemble da only. And other modifications are in

M       src/swell/tasks/run_jedi_local_ensemble_da_executable.py
M       src/swell/test/suite_tests/localensembleda-tier1.yaml

This PR does not affect variational runs.