Name `with_container_arithmetic` flags consistently

> I always have a hard time remembering which options correspond to the decorated container being the outer/inner structure. Might consider (at some point, doesn't have to be here) renaming so that everything is referenced in relation to the container, e.g., `number_bcasts_across`, `bcasts_across_obj_array`, `container_types_bcast_across`?

_Originally posted by @majosm in https://github.com/inducer/arraycontext/pull/190#discussion_r1710194416_