[bisect] Wire v2 bisection engine into the CLI

Integrates the experimental v2 bisection engine into the CLI under an
opt-in `--v2` flag. This commit connects the MOS interpolation,
assembly, and testing modules into a cohesive run loop in `lib.rs`.

Bug: b/487354432
Change-Id: I002241928bb0b921a1b68462b2f1f25a5279ca21
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1555600
Reviewed-by: Aidan Wolter <awolter@google.com>
Commit-Queue: Jerry Belton <jcecil@google.com>