* Autogenerate packet code in Rust from PDL (packet file copied from rootcanal)
* Implement parsing of packets that have a type header
* Expose Python APIs for sending HCI commands
* Expose Python APIs for instantiating a local controller
- Added Rust wrappers where relevant
- Edited a couple logs in python l2cap_bridge to be more symmetrical
- Created cli subcommand for running the rustified l2cap bridge
This contains Rust wrappers around enough of the Python API to implement Rust versions of the `battery_client` and `run_scanner` examples. The goal is to gather feedback on the approach, and of course to show that it is possible.
The module structure mirrors that of the Python. The Rust API is not optimally Rust-y, but given the constraints of everything having to delegate to Python, it's at least usable.
Notably, this does not yet solve the packaging problem: users must have an appropriate virtualenv, libpython, etc. [PyOxidizer](https://github.com/indygreg/PyOxidizer) may be a viable path there.
