add land constants as HISTORY export variables

[gmao-qliu]

Addresses #968, see for additional documentation.

Related PR: GEOS-ESM/GEOSgcm_App#636

The land constants collection defined in GEOS-ESM/GEOSgcm_App#636 matches the land constants file from MERRA-2 but now generated with MAPL HISTORY and with improved SHORT_NAME and LONG_NAME attributes.

The current file content is ok with @rdkoster and myself.

Zero-diff tests successfully conducted for AGCM and GEOSldas by @biljanaorescanin

Contents of sample land constants file verified by @gmao-qliu

@sdrabenh @biljanaorescanin @elakkraoui @rdkoster

[biljanaorescanin]

Testing summary:

1. Nightly GEOSldas tests
   All assim tests fail for run and comparison this is the run error:
   ERROR: cannot find export COND
   All model tests pass.

Here is path for one of the fails: /discover/nobackup/borescan/SystemTests/runs/LDAS_GLOBALCS/assim/CURRENT/scratch/GEOSldas_log_txt

UPDATED by @gmao-rreichle on 6 Aug 2024, 15:42h: After latest commits, GEOSldas tests pass.

2. 1 day AGCM AMIP, REPLAY and zero-increment REPLAY are all zero diff for data but metadata will make comparison fail due to the long name change.
   See more details below:
   Comparing NC4 catch_internal_checkpoint using nccmp... Failure! Checking for data differences Checking for metadata differences DIFFER : LENGTHS : ATTRIBUTE : long_name : VARIABLE : CDCR2 : 42 <> 46 : VALUES : "max_soil_water_content_above_wilting_point" : "maximum_soil_water_content_above_wilting_point" DIFFER : LENGTHS : ATTRIBUTE : long_name : VARIABLE : WPWET : 24 <> 48 : VALUES : "wetness_at_wilting_point" : "soil_wilting_point_in_degree_of_saturation_units"

3. regression on branch has passed

[biljanaorescanin]

Just a quick comment all GEOSldas nightly tests passed after last commit.