[Feature] Enhanced fluid flow to bottom tank

[EwyBoy]

Reference: #17

Also, particularly if auto output to other fluid handlers is not desired, there are ways to implement this behavior without requiring ticking at all [pushing or pulling fluids only after the fluid content is changed], or only requiring the bottom tank to tick, but that would be a much more involved change.

The push down behavior could also be made block state dependent [i.e. simply exit the tick method for BOT and ONE tank blocks], though this approach may be vulnerable to problems caused by cross-mod interactions resulting in the block states being arranged incorrectly.