feat: Add Discontinuous Galerkin (DG) discretization on Bernstein-Bézier tetrahedra and apply it to the acoustic wave propagator via SIPDG (Symmetric Interior Penalty DG)

feat: Add Discontinuous Galerkin (DG) discretization on Bernstein-Bézier tetrahedra and apply it to the acoustic wave propagator via SIPDG (Symmetric Interior Penalty DG) #9716