protocol: fully support

Currently some [valid protocol features](https://waterlinked.github.io/dvl/dvl-protocol/) are not supported or tested, including
- [ ] dead reckoning
- [x] ~reset dead reckoning~ command available via the DVL GUI in the frontend :-)
- [ ] ArduPilot's `VISION_POSITION_ESTIMATE` and `GLOBAL_POSITION_ESTIMATE` seem to be handled equally, so local positions may not be supported - needs confirmation/work, and can then be exposed as an output option via the frontend
- [x] ~gyro calibration~ command available via the DVL GUI in the frontend :-)
- [ ] handling different protocol versions

The best integrations are feature-complete, which this one is not.

Start with the linked DVL protocol documentation and inspect how ArduPilot's VISION_POSITION_ESTIMATE and GLOBAL_POSITION_ESTIMATE messages are currently handled. Confirm the expected local-position behavior, review protocol-version handling and the existing frontend DVL GUI options, then define completion as tested support for the listed valid protocol features.

Written by the indexing model from the issue text.