The ComponentBatch class introduced in #3791 is not actually specific to components at all. We should build it out to a "universal" container that we use in all codegen wherever we use std::vector right now.
It is also what all serialize methods should work with.

• [C++] Rename rerun::ComponentBatch to rerun::Collection (and related constructs) #4236
• Use rerun::Collection almost everywhere we'd use std::vector before #4247