New gamerule: PistonPushLimit

Hi, I suggest we add a PistonPushLimit gamerule in the next 1.17 snapshot which works like all non-boolean gamerules like randomTickSpeed or playersSleepingPercentage for example. It would be really useful for Redstone makers and if it gets added, you can set the gamerule to 0 for no push limit, or 1+ for a specific number of blocks that can be pushed at the same time, with 12 being the default value.