This MR adds support to run the GNN based tagger in Athena. The main changes can be summarised as -
OnnxUtilwhich can run onnx models using ONNXRuntime
OnnxUtilto decorate the btagging objects or the jets
DataPrepUtilitywhere we have functions that
GNNToolshare. The goal is to store the shared functions in one place and to improve the readability of the Tools themselves.