compatabiilty with FATES v2 nutrient API

[rgknox]

Description of changes

This set of changes only addresses changes to the history API and updates to the parameter file, to enable compatability with a new version of FATES. This set of changes does not add coupled N cycling with FATES (that will follow this).

This set of changes is synchronized with: NGEET/fates#880

Specific notes

Further modifications to this branch are necessary. 1) The associated FATES side PR is not currently next in queue, and an update to the default parameter file will precede the change included here. 2) We are debating the importance of having mapping variables in the history file for multiplexed variables. This PR introduces a new multiplexed fates dimension that is canopy-layer x size-class x pft (CLSZPF). We will probably, but not necessarily add mapping variables that connect this multiplexed dimension to the 3 component dimensions.

Contributors other than yourself, if any:

Many, see NGEET/fates#880

CTSM Issues Fixed (include github issue #):

none

Are answers expected to change (and if so in what way)?

Changes are only expected in fates tests where fates_parteh_mode = 2.

Any User Interface Changes (namelist or namelist defaults changes)? There may be updates to the list of variables included in testing.

Testing performed, if any:
(List what testing you did to show your changes worked as expected)
(This can be manual testing or running of the different test suites)
(Documentation on system testing is here: https://github.com/ESCOMP/ctsm/wiki/System-Testing-Guide)
(aux_clm on cheyenne for intel/gnu and izumi for intel/gnu/nag/pgi is the standard for tags on master)

NOTE: Be sure to check your coding style against the standard
(https://github.com/ESCOMP/ctsm/wiki/CTSM-coding-guidelines) and review
the list of common problems to watch out for
(https://github.com/ESCOMP/CTSM/wiki/List-of-common-problems).

[rgknox]

aux_clm tests seem nominal, nlcomps are expected and diffs with base are expected with fates tests:
/scratch/cluster/rgknox/tests_1201-122133iz
/glade/scratch/rgknox/tests_1201-121507ch

[ekluzek]

The changes here are really straightforward, and not much to say about it. The real changes are likely inside of FATES.

The only nitpick I saw was that there's some whitespace at the end of lines. This is the sort of thing that we could use a pre-commit filter to help us with.

[ekluzek]

I did my normal double checking, the 21 cheyenne and 10 izumi Fates tests passed, with expected answer changes.