Bug/issues in the marine ensemble re-centering application

[guillaumevernieres]

• It produces full ocean fields instead of increments:
  Something is probably wrong in the yaml configuration here: soca_ensrecenter.yaml
• Missing the seaice re-centered analysis

Notes:

• @AndrewEichmann-NOAA , there is a bug in the "increment handler", the fix is in feature/marineenvar. That's the reason why we are getting full fields instead of increments.
• The deterministic background for the re-centering (letkf to fcst) needs to match the time for which the ens. mean is computed
• Check if the re-centering increment's sign is correct.