use mavio instead of rust-mavlink

[roby2014]

rust-mavlink has a bad issue for now: dialect being always necessary when creating a mavlink connection.

https://mavka.gitlab.io/home/projects/mavio/

Mavio is a building block for more sophisticated tools. It is entirely focused on one thing: to include absolute minimum of functionality required for correct communication with everything that speaks MAVLink protocol.

Mavio has versionless features and dialect-agnostic as well. The author also has another tools to parse MAVLink xml definitions.
This looks like a great lib for this project use-case.

Start slowly migrating from rust-mavlink.