Add archetype_native attribute and make ContainerBlueprint eager + partial

[teh-cmc]

Introduces a new attribute that, when paired with an eager archetype, will also generate a native companion type with back-and-forth conversion methods.

This is especially useful for blueprint archetypes (although there are definitely non-blueprint examples too), which are heavily used all across the viewer, and would be very painful to use otherwise.

/// Whether we should generate an extra Rust object comprised of native Rust types.
///
/// The generated object will have the name of the archetype, prefixed by `Native`,
/// e.g. `NativePoints3D`.
///
/// Applies only to *eager* archetypes. No-op otherwise.
attribute "attr.rust.archetype_native";

With this, we now should have all the tools required to port every remaining archetype (both blueprint and data).

• Part of Eagerly serialized, partially updatable 2D & 3D line strips #8650

[teh-cmc]

Ha yeah I also ported VisualBounds2D and Background because it didn't require any particular effort.

[github-actions]

Web viewer failed to build.

| Result | Commit | Link | Manifest |
| ------ | ------- | ----- |
| ❌ | | https://rerun.io/viewer/pr/8666 | +nightly +main |

^{Note: This comment is updated whenever you push a commit.}

[emilk]

Nice!

[emilk]

What do you mean? Why would cargo fmt produce 1000 lines?

[teh-cmc]

rustfmt splits method chains no matter their length, so all the value.#field_name.clone().map(|batch| (batch.descriptor, batch.array)) emitted by this method turn into 4 lines each, which is really pushing it.

[teh-cmc]

As opposed to this neat little block 😊