Add implict solver for diagnostic EDMF

[dennisYatunin]

Purpose

This PR extends #2379 to diagnostic EDMF.

Content

• Move the diffusion of TKE into the edmfx_sgs_diffusive_flux_tendency!.
• Move the edmfx_sgs_diffusive_flux_tendency! into the implicit tendency when implicit_diffusion is true.
• Add the diffusion matrix for TKE to the Jacobian, and simplify how the diffusion matrix for ρe_tot is set. In addition, add an advection matrix for TKE to the Jacobian, but set this matrix to 0 since the advection of TKE is not currently implicit.
• Add a new config option approximate_linear_solve_iters for setting the number of iterations of the linear solver when implicit_diffusion is true. The default value for this option is 1.
• Update the diagnostic EDMF examples in the pipeline so that they set implicit_diffusion to true. Most of these also require setting approximate_linear_solve_iters to 2 in order to produce reasonable results.

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

[szy21]

Thanks for the assert which shows a few mistakes in the current config files:) Fixing them here: #2403