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?