[request]: Use `uuid::Uuid` instead of `String` for UUIDs

It would be nice if UUIDs were typed more strictly than just `String`.
The `uuid` crate is ubiquitous for this purpose.

If the extra dependency is a concern, then it could be enabled as a feature in `Cargo.toml`.
`postgres` has a `with-uuid-0_8` feature.

Start by reviewing Cargo.toml and the SDK's UUID-related type definitions and generated API surfaces. Check how the postgres with-uuid-0_8 feature could inform dependency handling. Done means UUID fields use uuid::Uuid instead of String, with the dependency or feature configuration working across the affected SDK APIs.

Written by the indexing model from the issue text.