rrfs.v1.0.0 release branch update with GDIT's performance optimization

[ShunLiu-NOAA]

Description

Please see GSI PR #811 for details.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• New and existing tests pass with my changes
• Any dependent changes have been merged and published

[ShunLiu-NOAA]

I completed a full set of tests with the rrfsv1 configuration:

1. control: no gdit modification, walltime 1162s
2. exp1: with gdit modification, but without using xnorm_new and anl_grid, walltime 908s
3. exp2: with gdit modification and using xnorm_new and anl_grid, walltime 730s
   All three experiments use 30 regional ensembles and 50 iteration for two minimization cycles. "cost,grad,step,b,step? = 2 50" are bit-identical.

gsi stdout and fort.2* files are in /lfs/h3/emc/lam/noscrub/emc.lam/stmp/rrfs/v1.0.0/anal_conv_dbz_gsi

1. fit_ctl
2. fit_gdit_no_optimization
3. fit_gdit_optimization/

I think it is ready to merge this to the rrfsv1_release branch.

[ShunLiu-NOAA]

@hu5970 @TingLei-NOAA Let me know if you have any further concern about this PR.