Remove option to pass averaged normal direction for NonConservativeJump terms

[patrickersing]

See #2852

This PR modifies the calcflux_fhat! kernel for NonConservativeJump() terms to pass the left and right normal direction instead of the averaged normal direction, to fix the convergence issues on curvilinear meshes.
This also required a modification of how the normal direction is applied for flux_nonconservative_powell_local_jump.

Here are convergence results for elixir_mhd_alfven_wave_curved_sc.jl with polydeg=4, dt=2e-4 at time t=0.1:

TODO:

• TrixiShallowWater.jl: Create PR to adapt the arguments for flux_nonconservative_ersing_local_jump

[github-actions]

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.09%. Comparing base (4c42b01) to head (d4ee190).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2890   +/-   ##
=======================================
  Coverage   97.09%   97.09%           
=======================================
  Files         609      610    +1     
  Lines       47493    47497    +4     
=======================================
+ Hits        46111    46116    +5     
+ Misses       1382     1381    -1     

Flag	Coverage Δ
unittests	97.09% <100.00%> (+<0.01%)	⬆️

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