1719 - Implement tag_dispatch::for_each

[icui]

Description

• Implement tag_dispatch::for_each_in_product
• Apply to compute_stiffness_interaction

specfem::tag_dispatch::for_each<
    specfem::tag_dispatch::dimension_set<DimensionTag> *
    specfem::tag_dispatch::medium_set<MediumTag> *
    PROPERTY_T(isotropic, anisotropic, isotropic_cosserat) *
    BOUNDARY_T(none, stacey, acoustic_free_surface, composite_stacey_dirichlet)>([&]<typename Tags>() {
    if constexpr (DimensionTag == Tags::dimension_tag &&
                    MediumTag == Tags::medium_tag) {
        elements_updated += compute_stiffness_interaction_core<
            NGLL, Tags>(assembly, istep);
    }
});

Not implemented in this PR, but element_types will look like

class ElementTypes {
public:
  static constexpr auto ET =
      DIMENSION_T(dim2) *
      MEDIUM_T(elastic_psv, elastic_sh, elastic_psv_t, acoustic, poroelastic, electromagnetic_te) *
      PROPERTY_T(isotropic, anisotropic, isotropic_cosserat) *
      ATTENUATION_T(none, constant_isotropic) *
      BOUNDARY_T(none, stacey, acoustic_free_surface, composite_stacey_dirichlet);

...

int total_elements() const {
    int total = 0;
    specfem::tag_dispatch::for_each(ET, [&]<typename Tags>() { total += elements.get<Tags>().extent(0); });

    // we could also do
    //  return elements.reduce([](int sum, const auto& view) { return sum +
    //  view.extent(0); });
    return total;
  }

Issue Number

Adds to #1719

Checklist

Please make sure to check developer documentation on specfem docs.

• I ran the code through pre-commit to check style
• THE DOCUMENTATION BUILDS WITHOUT WARNINGS/ERRORS
• I have added labels to the PR (see right hand side of the PR page)
• My code passes all the integration tests
• I have added sufficient unittests to test my changes
• I have added/updated documentation for the changes I am proposing
• I have updated CMakeLists to ensure my code builds
• My code builds across all platforms