It should be possible to start using the new object-oriented Points2D archetype from the current Rust SDK, today.

This must coexist peacefully with the existing MsgSender API.
I.e. going through the old MsgSender or through the new object API should both be legal and behave similarly.

This will allow us to start migrating step-by-step to both the object-oriented API and the codegen stack.

Requires #2383