Implement subcell limiting for non-conservative systems using curvilinear solvers

[amrueda]

This PR extends the subcell limiting capabilities of Trixi.jl for non-conservative systems to the curvilinear solvers based on StructuredMesh and P4estMesh.

To do the subcell limiting, the DGSEM is formulated as a flux-differencing formula. For non-conservative systems, this formulation requires expressing non-conservative terms as the product of local and symmetric components (#1670) or the product of local and jump components (#2429). See, e.g.,

• Rueda-Ramírez, Gassner (2023). A Flux-Differencing Formula for Split-Form Summation By Parts
  Discretizations of Non-Conservative Systems. https://arxiv.org/pdf/2211.14009.pdf.

[github-actions]

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Created with ❤️ by the Trixi.jl community.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.83%. Comparing base (53c4725) to head (473ffbb).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2051      +/-   ##
==========================================
+ Coverage   96.80%   96.83%   +0.03%     
==========================================
  Files         501      502       +1     
  Lines       41390    41737     +347     
==========================================
+ Hits        40066    40413     +347     
  Misses       1324     1324              

Flag	Coverage Δ
unittests	96.83% <100.00%> (+0.03%)	⬆️

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[patrickersing]

Below are convergence results for p4est_2d_dgsem/elixir_mhd_alfven_wave.jl with VolumeIntegralSubcellLimiting.

flux_powell_local_symmetric, polydeg=4, dt=1e-4:

flux_powell_local_symmetric, polydeg=5, dt=1e-4:

flux_powell_local_jump, polydeg=4, dt=1e-4:

flux_powell_local_jump, polydeg=5, dt=1e-4:

[amrueda]

Many thanks for completing this, @patrickersing. I leave some minor comments here. Since this is a PR that I started, I cannot approve it 😅 and we will need one more review. Would you have time to check this, @andrewwinters5000?

[andrewwinters5000]

It looks good overall, I just left a few small suggestions in formatting the comments.

[patrickersing]

@amrueda @andrewwinters5000 Thanks for reviewing! Now everything should be addressed.

[andrewwinters5000]

LGTM!