(core): add isInsideThetrahedron method with baricentric coordinate
Description
The MeshFunction dispose of a method which allows to compute the barycentric coordinates from a point and a tetrahedron coordinates. It has in addition a method which checks if a point is inside a tetrahedron, with the same signature, by computing the barycentric coordinates, and applying a coordinates test.
However, a usage could be to test if a point is inside à tetrahedron, and, if true, make use of the barycentric coordinate. This implies to compute the barycentric coordinate twice.
Proposal
To prevent this, and improve the computation time of the algorithm, the proposition is to add a method which test if a point is inside a tetrahedron, based on the barycentric coordinate directly. This would allow to use the same method as the original one, or the new one, which allow testing and use the barycentric coordinates directly.