Allow for lower MinFinalPtCut in combinatorial track finder if needed

As part of the investigations in ATLHI-502, @mdyndal observed a minimal pT cut has been introduced in the track finder in r22, as part of !56561 (merged) for FPE protection, with a default value of 100 MeV. For configurations like UPC Pixel pass attempting very low pT reconstruction, this would limit the reconstruction efficiency so the configuration is updated accordingly. This fixes the issue observed previously with pixel tracks now reconstructed down to 50 MeV.