Implement a BLE scan parser in Rust

This should match the behavior of the original C++ parser, with the
exception of the open question around UTF-8 advertisement names.
Followup CLs will:
- figure out what to do with the UTF-8 business
- add a differential fuzzer
- add a feature flag to toggle which parser is used

Bug: 422329505
Change-Id: I004130a4ab8c90dbcf388b7e09fa2e7e8412f10e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6619135
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Commit-Queue: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1470752}