Allow use of rerun::CollectionAdapter on archetype mono component fields

[Wumpf]

Archetypes consist of rerun::Collection<ComponentType> for every component that is not a so called "mono component". Common examples for this are image, transform and mesh.

This means that you can write an adapter that allows you to log your points, making rerun::Points3D(myPoints) work for arbitrary types, but the same can't be achieved with rerun::Image(myImage) since there is no way to enhance this with an adapter.

From a performance stand point we already solved the main concerns: Buffers within image and mesh are rerun::Collection and thus they can be adapted and/or borrow arbitrary data.
For ergonomics this is still problematic though!