NCI mortar transfer

[int-ptr-ptr]

Task description

Write a list of things that need to be completed to achieve the goal of this issue.

• specfem::coupled_interface::transfer::set_transfer_functions(mortar_transfer_view, adjacency_graph_edge, elem_quadrature, mortar_quadrature) -> void - delegates to compute_intersection to find the mortar, then builds the mortar transfer from the element (GLL) and mortar quadratures.
• Revive unit-tests/mortar with tests:
  • set_transfer_functions properly give mortar transfer functions:
    • for affine-transformed elements, mortar transfer of basis functions (polynomials) give polynomials of same degree. Are the roots in the same global coordinates?

Acceptance criteria

• The test passes