This works like PQkFiniteElementCache in dune-loicalfunctions
but also allows to obtain raw fe-implemenations without polymorphic
wrapper if the geometry type is provided statically as StaticGeometryType.
This allows to seamlessly switch between the polymorphic and non-polymorphic
version by using GeometryType or StaticGeometryType.

The StaticGeometryType imlementations are stored in a TupleVector.