std: remove BoundedArray

All of the places this data structure was used were improved by not
using this data structure.

Furthermore, I don't like it. So now it's gone.

If you want to continue using it, copy it into your project, or
collaborate to maintain it as a package and add it as a dependency to
your project.

Otherwise, use ArrayList, or slices and arrays directly, which ends up
being more ergonomic anyway.