feat: introduce or-pattern syntax for defining patches

[ericszentivanyi]

This PR introduces an or-pattern syntax, allowing the same patch to be applied to multiple generated types.

Example

import_types!(
  schema = "../schema.json",
  patches = {
    Foo | Bar = {
      derives = [/* ... */],
    },
  },
);

[ahl]

How would this work if rename is specified?

[ericszentivanyi]

How would this work if rename is specified?

Good question. This would require a simple restriction preventing patches that use the or-pattern from specifying renames when applied to multiple types. I used PatchType as the foundation for implementing variant patches (via a PatchType::Path variant), so rename is still supported for variants, but not when applied to types.

Similarly, variant patches should not be able to specify derives, so I added a restriction for that as well. Let me know if you would like me to implement something similar.

[ahl]

So the use case here is that you have a bit chunk of the generated types for which you want an additional derive macro applied? Many, but not all?

[ericszentivanyi]

So the use case here is that you have a bit chunk of the generated types for which you want an additional derive macro applied? Many, but not all?

Yes, some macros (e.g. wasm_bindgen) do not support certain data types, so they would need to be applied via a patch, and it would be useful if this patch were not duplicated.

That is my use case.