Refactor fluid slot filling/draining logic & better support for IFluidContainerItem

[danyadev]

This refactor is divided into several commits, with each having a description of what was done there. Though be warned that methods were basically rewritten so there's no point in comparing them with old code line by line

The main reason for this refactor is to support IFluidContainerItem various use cases. Previously, these containers were treated as normal containers and could only be filled or drained by their full capacity. Now, they can be filled/drained in any way imaginable:

• to fill the slot up to its capacity
• to fill the container up to its capacity

Let's look at an example:

• there's a fluid slot that can hold 32,000 L of fluid, currently empty
• you're holding 10 Large Steel Cells, each filled 5,000 L out of 8,000 L
• when you try to put these Cells in a fluid slot (using Shift to apply the whole stack), at first it tries to consume whole items: 5,000 * 6 = 30,000 L and returns to you 6 empty Cells. Then it picks one Cell and tries to apply it too: 2,000 L can be filled in and in return it gives you a Cell with 3,000 L