Better water & drains

remember the more realistic water physics shown in minecon 2017, but wasn't implemented due to people worrying about the farms that would break, well what if they made a block (which we shall call a drain) that create blocks around the drain, that act like the air block, but doesn't allow water through, these fake air blocks could be replaced by just placing blocks on it, like grass (not block) this will be very nice to have