Fix creative tanks only outputting up to 1kL at a time

[Zorbatron]

What

Fixes an issue with #1963 which made it so creative tanks would only push 1kL of fluid at a time.

Implementation Details

Is overriding getFluid in the creative tank handler a good idea or would it be better to re-add the stack.amount = mBPerCycle; that was removed in #1963?

Outcome

Creative tanks work again.

[ghzdude]

i don't know how to feel about copying the fluid stack every time getFluid() is called. it might be better use the drain method instead of using getFluid() since drain essentially does the same thing

[Zorbatron]

Do you think

FluidStack stack = fluidTank.getFluid();
int canInsertAmount = fluidHandler.fill(stack, false);
stack.amount = Math.min(mBPerCycle, canInsertAmount);

fluidHandler.fill(stack, true);

is even needed? I think that it could just be replaced with

fluidHandler.fill(fluidTank.drain(Integer.MAX_VALUE, false), true);

[ghzdude]

fluidHandler.fill(fluidTank.drain(Integer.MAX_VALUE, false), true);

i think this is good enough, but with mbPerCycle instead of max int