#1664 Rename the VertexCoordsList CoordsList: the notion was completely meaningless with the most recent versions of the library.

#1664 Coords: remove the interface nature from the API: it was deprecated with the changes of current ticket so no need to keep it.

#1678 Investigate to check  there is nothing amiss in the library (there's not). Some comments have been improved in the process - and some typo fixed. Test has ot yet been modified to pass.

#1586 Removed CurvilinearHyperelasticity operator as it is now depracted and replaced by the NonLinearShell operator using None as the tying points policy.

#1664 Moved the mesh used for the CurvilinearHyperelasticityOperator test and updated its description.

#1664 TyingPointDataForComponent objects now compute the relevant local quantities at quadrature points when there is no specific interpolation at tying points. Greatly simplifies the API in the NonlinearShell operator (at the cost of some unnecessary copies during initialization).

#1664 Shell operator now correctly handles cases where the test function is not the same as the displacement one. Some further refactoring can be done for the TyingPointDataForComponent class so that it also computes the values at the quadrature points directly when there is no specific interpolation for a component (at the time it is the NonlinearShellOperator itself that does the computation through constexpr evaluations).

#1660 Tying point data now treated as a policy. Still have to deal with the cases where not every component of the strain tensor are interpolated (for MITC9 Q1P2 for instance) through constexpr evaluations.

#1660 Refactored tying point data in a standalone object, which will be used as a policy for the Shell operator in order to choose an interpolation rule.

#1664 Shell operator implemented for Q2 elements, after a long due rebase on master. Tying points policy needs to be added and documentation remains to be improved.

#0 Implemented some temporary outputs in the ModelInstances for the validation of the Shell operator.