Add current inventory report

[blimpich]

This is another big feature that would require a lot of upfront scoping and questions in order to figure out exactly what it is and how to do it. In its most basic sense, its simply keeps track of what the food bank has at that moment in time sitting in their food bank, but the current app doesn't add an subtract from an inventory, it just keeps track of whats coming in and whats going out, there is no middle right now where that stuff is stored.