Atlas upgrade extrapolator [ATLIDTRKCP-387]
This MR aims at rationalising the Extrapolator configuration for the Run-4 reconstruction, as discussed in ATLIDTRKCP-387. The new AtlasUpgradeExtrapolatorCfg uses the ITkPropagatorCfg and ITkMaterialEffectsUpdatorCfg for the ITk part while the other subdomains inherit their configuration from the existing AtlasUpgradeExtrapolatorCfg. Alternative configurations for the Egamma and MCTruthClassifier extrapolators are also provided. The configuration of the subtools is centralised in the same config file to avoid duplication and possible divergences.
No difference is observed for ITk tracks when run with the reconstruction.