RootCanal: Implement LMP as a rust library

The implementation is switched from a custom
Link Layer Protocol to LMP to be more close to
the specification.

This is implemented under a feature flag because
currently we are unable to use Rust inside the emulator
so we keep the old implementation for the emulator
until we find a better solution.

This is implemented in Rust to have access to
coroutines (via async/await) to ease the implementation.

Bug: 216620310
Bug: 209804169
Bug: 209803517
Test: Run AVDTP/SNK PTS-bot tests on Eiffel
Change-Id: Ib2795ea31fe3658e4dafb0cf9ea41f473291b8c0