Add electron ID DNN outputs to derivations (ATLEGAMDPD-168)

Adding the six outputs and three working points of the multiclass DNN for electron ID to derivations. To get the six outputs out of the tool a new method is added which returns a vector of outputs instead of a single output (in rel 21 the TResult could be used for that). The tools that don't have multiple outputs but the same interface will return a vector of only one element.

Closes ATLEGAMDPD-168