WIP: Tau track sequence dev

Hello, I'm creating this MR in order to trigger the discussion on the TrackSequence steps of the tau trigger which is ongoing in JIRA https://its.cern.ch/jira/browse/ATR-17399. This MR should be merged after !21249 (merged). Cheers, Edson Tagging the relevant people here: @fpastore @tbold @mvozak @zgrout @martindl @guindon