*****ZIGGY-SIZED SPOILERS!***** NBC/Peacock’s revived “Quantum Leap” just ended its second season, leaving the door wide open for a third, but given its uncertain future, this might be a series finale as well. The original Quantum Leap (1989-1993) was a time-traveling anthology series following the quest of Dr. Sam Beckett (Scott Bakula) to right past wrongs…