RD: add flavour tagging extra_outputs for spruce line
Adding extra_outputs_for_FlavourTagging_ForSprucing
for saving tagging results and tagging particles in extra_outputs of spruce line b_to_xgamma_exclusive_spruce
, following the instructions from FT group.
The previous MR
https://gitlab.cern.ch/lhcb-dpa/project/-/issues/243, https://gitlab.cern.ch/lhcb-dpa/project/-/issues/78
Edited by Eduardo Rodrigues