Improve debugging of `ldiv`

[charleskawczynski]

I don't know for sure if this should be a ClimaCore or ClimaAtmos issue, so we can move this if it makes sense.

It would be nice if we could somehow "name" broadcast expressions in our MatrixField infrastructure so that we can more easily debug things passed to ldiv:

[1] error(s::String)
--
  | @ Base ./error.jl:35
  | [2] (::ClimaCore.MatrixFields.var"#119#120"{Tuple{…}})(entry::Array{Float32, 5})
  | @ ClimaCore.MatrixFields /central/scratch/esm/slurm-buildkite/climaatmos-ci/depot/default/packages/ClimaCore/K4gqi/src/MatrixFields/field_name_dict.jl:47
  | [3] macro expansion
  | @ /central/scratch/esm/slurm-buildkite/climaatmos-ci/depot/default/packages/Unrolled/KtWta/src/Unrolled.jl:47 [inlined]
  | [4] unrolled_foreach(f::ClimaCore.MatrixFields.var"#119#120"{…}, seq::Tuple{…})
  | @ Unrolled /central/scratch/esm/slurm-buildkite/climaatmos-ci/depot/default/packages/Unrolled/KtWta/src/Unrolled.jl:127
  | [5] ClimaCore.MatrixFields.FieldNameDict(keys::ClimaCore.MatrixFields.FieldMatrixKeys{…}, entries::Tuple{…})
  | @ ClimaCore.MatrixFields /central/scratch/esm/slurm-buildkite/climaatmos-ci/depot/default/packages/ClimaCore/K4gqi/src/MatrixFields/field_name_dict.jl:46
  | [6] (ClimaCore.MatrixFields.FieldMatrix)(::Pair{Tuple{…}, LinearAlgebra.UniformScaling{…}}, ::Vararg{Pair{…}})
  | @ ClimaCore.MatrixFields /central/scratch/esm/slurm-buildkite/climaatmos-ci/depot/default/packages/ClimaCore/K4gqi/src/MatrixFields/field_name_dict.jl:56
  | [7] ClimaAtmos.ImplicitEquationJacobian(Y::ClimaCore.Fields.FieldVector{…}, atmos::ClimaAtmos.AtmosModel{…}; approximate_solve_iters::Int64,