Tau PHYSVal monitoring, make tighter nominal tau selection
Tau PHYSVAL monitoring currently has two tau selections: "primitive" and "nominal" selection.
Currently the two selections are differing only in the tau pt and the tau eta requirement, making the two selections largely overlapping. This MR is tightening the "nominal" selection, applying tighter tau track selection with nTracks <= 3. This would reduce the overlap and bring the "nominal" selection closer to real analysis selection