fix(functors): TES functor, ensure DataHandle has usable C++ type
Make sure that the DataHandle
passed to a TES functor knows its C++ type, otherwise we can't create correct C++ code for the Functor.
Independent, but the help message points the user to the feature implemented in LHCb!3643 (merged).
Let's just test them together.
NEEDS Analysis!899 (merged)
Edited by Christoph Hasse