Export TensorBuffer & TensorDimension to rerun namespace (#4331)

### What

What it says on the tin. Makes user code/example a little bit nicer


### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested [demo.rerun.io](https://demo.rerun.io/pr/4331) (if
applicable)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG

- [PR Build Summary](https://build.rerun.io/pr/4331)
- [Docs
preview](https://rerun.io/preview/aaf4036f3ccae78994d61927eab954d85ff3825b/docs)
<!--DOCS-PREVIEW-->
- [Examples
preview](https://rerun.io/preview/aaf4036f3ccae78994d61927eab954d85ff3825b/examples)
<!--EXAMPLES-PREVIEW-->
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

crates/rerun/src/sdk.rs

@@ -28,9 +28,9 @@ mod prelude {
         TextLogLevel, Vector3D,
     };
     pub use re_types::datatypes::{
-        Angle, ClassDescription, Float32, KeypointPair, Mat3x3, Quaternion, Rgba32, Rotation3D,
-        RotationAxisAngle, Scale3D, TranslationAndMat3x3, TranslationRotationScale3D, Vec2D, Vec3D,
-        Vec4D,
+        Angle, AnnotationInfo, ClassDescription, Float32, KeypointPair, Mat3x3, Quaternion, Rgba32,
+        Rotation3D, RotationAxisAngle, Scale3D, TensorBuffer, TensorData, TensorDimension,
+        TranslationAndMat3x3, TranslationRotationScale3D, Vec2D, Vec3D, Vec4D,
     };
 }
 pub use prelude::*;

rerun_cpp/src/rerun.hpp

@@ -51,7 +51,9 @@ namespace rerun {
     using datatypes::Rotation3D;
     using datatypes::RotationAxisAngle;
     using datatypes::Scale3D;
+    using datatypes::TensorBuffer;
     using datatypes::TensorData;
+    using datatypes::TensorDimension;
     using datatypes::TranslationAndMat3x3;
     using datatypes::TranslationRotationScale3D;
     using datatypes::Vec2D;