libadsb-reader 0.1.44

- Adds a bounded 8192-frame producer/consumer message cache to RTL-SDR.
- Receive/demod no longer executes application callbacks synchronously.
- Verbose telemetry reports current cache fill, high-water mark and dropped frames every five seconds.
- Public API exposes current/capacity/peak/dropped queue statistics and peak reset.
- RadarBox existing queue is exposed through the same API.
- Preserves 0.1.43 behavior plus the 0.1.119Fix7 raw-less confirmed-contact collector path.
