Extend Vcmax to support SpaceVaryingInput

[imreddyTeja]

Purpose

FarquharParameters now also supports Vcmax25 of type ClimaCore.Fields.Field. In relevant tests, Vcmax25 is changed from a float to a field that contains the previous Vcmax25 value everywhere. Both longrun and benchmark Land.jl now use the Vcmax map from clm_data.
Closes #723

PR also contains whitespace removal.

To-do

• Add VCmax map to ClimaArtifacts

Content

• FarquharParameters takes a Vcmax25 of type F <: Union{<: AbstractFloat, ClimaCore.Field}
• Land.jl benchmark and long run uses the vcmax map from clm_data. Map can be seen below.
  
• Relevant tests now use field of constant values for Vcmax25.

Example output of experiments/long_runs/land.jl

Previously:

After changing Vcmax25 to the clm_data map:

---

• I have read and checked the items on the review checklist.

[kmdeck]

do we need this FT? If Vcmax25 is a field, it should already be made on the space of the simulation and be the right type. If it is a scalar, this definition in the FarquharParameter struct VC <: Union{FT, ClimaCore.Fields.Field} should ensure it is the same type as the other scalars.

[imreddyTeja]

I think Julia did not want to perform conversion from scalars to a union of a scalar and a non-scalar. If I remove line 169 the tests fail with
TypeError: in FarquharParameters, in VC, expected VC<:Union{Float32, ClimaCore.Fields.Field}, got Type{Float64}. Additionally, if I try converting from a scalar to Union{FT, ClimaCore.Fields.Field} I get
MethodError: Cannot convert an object of type Float64 to an object of type Union{Float32, ClimaCore.Fields.Field}

[kmdeck]

This looks good to me, thank you!

We must already broadcast over functions with VCmax25 in Canopy.jl, since that didnt need to change?

[Sbozzolo]

Make sure to add an entry to the NEWS file too. When you do so, it is nice if you can showcase the new feature you have added (see, e.g., how we do it in ClimaAnalysis).

[AlexisRenchon]

beautiful! thanks @imreddyTeja