Make AtmosModel more structured

[charleskawczynski]

I looked at specializations (following https://timholy.github.io/SnoopCompile.jl/dev/tutorials/pgdsgui/), and it seems that julia is overspecializing the AtmosModel, likely because there are too many type parameters:

julia> t, m = tms[end-7]
(5.9745849170000005, var"#AtmosModel#36"(model_config, moisture_model, precip_model, cloud_model, call_cloud_diagnostics_per_stage, forcing_type, subsidence, ozone, radiation_mode, ls_adv, external_forcing, edmf_coriolis, advection_test, tendency_model, edmfx_model, turbconv_model, non_orographic_gravity_wave, orographic_gravity_wave, hyperdiff, vert_diff, diff_mode, sgs_adv_mode, viscous_sponge, rayleigh_sponge, sfc_temperature, insolation, surface_model, surface_albedo, numerics, ::Type{ClimaAtmos.AtmosModel}) @ ClimaAtmos ~/Dropbox/Caltech/work/dev/CliMA/ClimaAtmos.jl/src/solver/types.jl:392)

As a result, creating this object takes 5.97 seconds, which seems pretty long.

We should probably convert if from a flat datastructure to a more structured one. For example, what I'd preliminarily propose is:

    config
        numerics::NUM = nothing
        model_config::MC = nothing
    moisture::MM = nothing
        moisture_model::MM = nothing
        precip_model::PM = nothing
        cloud_model::CM = nothing
            call_cloud_diagnostics_per_stage::CCDPS = nothing
    forcing::F = nothing
        forcing_type::F = nothing
        subsidence::S = nothing
        external_forcing::EXTFORCING = nothing
    radiation::RM = nothing
        radiation_mode::RM = nothing
        ozone::OZ = nothing
        insolation::IN = nothing
    advection::A
        ls_adv::LA = nothing
        advection_test::AT = nothing
    tendency_model::TM = nothing
    turbconv::TCM = nothing
        edmf_coriolis::EC = nothing
        edmfx_model::EDMFX = nothing
        turbconv_model::TCM = nothing
        sgs_adv_mode::SAM = nothing
    gravity_wave::NOGW = nothing
        non_orographic_gravity_wave::NOGW = nothing
        orographic_gravity_wave::OGW = nothing
    hyperdiff::HD = nothing
    vert_diff::VD = nothing
        diff_mode::DM = nothing
    sponge::SP = nothing
        viscous_sponge::VS = nothing
        rayleigh_sponge::RS = nothing
    surface::SU
        sfc_temperature::ST = nothing
        surface_model::SM = nothing
        surface_albedo::SA = nothing

This would reduce type parameters of AtmosModel from 29 to 12.