Add support for default components

[mat-1]

The data_components.py codegen now additionally writes to azalea-inventory/src/default_components/generated.rs with DefaultableComponent impls for every component that has default implementations for any items, by translating Mojang's items.json to Rust values.

It's optimized to generate different impls based on some heuristics, so for some components it'll use a lookup table and for others it'll write a match statement. I don't expect that the codegen will need to be changed for most updates, except for when Mojang adds another more unusual looking components.

Note that this approach has the downside of making it more complicated to get a list of default components for an item (because you'd have to call default_for_item for every DefaultableComponent), but I don't expect this to be a common case (since usually you only care about a single component at a time).