Remove deprecated utilities and code

[aerorahul]

This PR:

• removes enkf_chgres_recenter.fd/
• removes regrid_nemsio.fd/
• removes fv3nc2nemsio.fd/
• removes nemsio capability and dependency from gaussian_sfcanl.fd/

Updates to gaussian_sfcanl.fd requires an update to the shell scripts calling the executable in the global-workflow.
Specifically:

• netcdf_out namelist variable is removed
• do_nst variable is now a logical (.true.|.false.) instead of yes|no.

The only remaining nemsio dependency utility is gfs_bufr.fd.

Partially addreses #9