Rewrite of KalmanMET in L1Topo Simulation

KFMET was never fully commissioned for legacy L1Topo in Run2 and the desired prescription of this algorithm was slightly changed for Run3 / Phase1 L1Topo. Hence, the firmware algorithm and its simulation counterpart were essentially fully rewritten. The latter rewrite is contained in this MR. Following the deployment of Ph1Topo FW v10.0.1 a local Athena build including the changes in this MR was used to asses the FW/Sim agreement using 100k events from run 473915. Firmware and simulation results are found to be in full agreement with between 20-40% accepted events (depending on exact KFMET threshold) in the sample used (roughly comparable to other MET triggers with similar thresholds)