moving pistons can change position while tick frozen by pressing esc

my guess is that pressing esc resets tick delta. Could be quite straightforward to fix, but that would only be a client side fix needed here.

Its actually very visible when not frozen

/tick rate 1
/carpet smoothClientAnimations true
pressing exc constantly resets piston position each tick to the fixed positions that would be at the edge of a tick.

Duplicate of #703.

Internally they are not changing, it's only visual render delta.