0.23.0

(feat): Generate builders for all struct types. The builder pattern is inspired by other popular Rust SDKs (e.g. AWS), so that users now have the option between the following:

  1. The explicit constructor pattern (i.e. specify None values for optional fields).
  2. The ..Default::default() spread when a type has many optional fields.
  3. The builder pattern when a type has many optional fields and cannot support the ..Default::default() approach.