Allow copper items to be smelted back into copper

I did the math and one cut copper slab using the stonecutter is quivalent to 1.125 copper ingots. This means that it would not be an exploit to allow people to resmelt it into a copper ingot.

Why do I propose this? Copper building ends up being such a burden due to the fact every distinctly oxidized item counts as a different item. Due to this, it is not uncommon to end up with maybe "9 exposed cut copper stairs", a very niche block that you are unlikely to sort automatically and becomes a burden. Allow us to smelt all stairs, slabs, chains and cut copper blocks back into ingots. Yes, you'd lose copper, but that's okay, it's a tradeoff for recycling the blocks. For copper bars smelting one could give you a copper nugget.