Add option to recenter marine LETKF increments and use to initialize ensemble

[AndrewEichmann-NOAA]

What new functionality do you need?

Add the option to use the increments from the marine LETKF to recenter around the deterministic analysis and use the result to initialize the ensemble.

Acceptance Criteria

• When option is enabled, have marine ensemble increments differ from the the ones produced when not enabled, and cycle accordingly.

Suggest a solution (optional)

No response

[AndrewEichmann-NOAA]

@shlyaeva @guillaumevernieres Anything to add to this?