Make derivative of LocalFunction bound to an element if the LocalFunction iself is bound
summary
This follows the implementation of https://gitlab.dune-project.org/staging/dune-functions/-/merge_requests/355 and the discussion https://gitlab.dune-project.org/staging/dune-functions/-/issues/69
This MR allows to use the derivative of a localfunction (that was already bound to an element) directly as function (Without any additional call to bind()
. Eventually, this will simplify the implementation of LocalFunctionGeometry
.