Dev: list firmware-supported MAVLink messages and commands

[ES-Alexander]

Near term:

• Create firmware source parser for messages and commands that each vehicle type handles and/or sends
  • Tools: scripts: Update MAVLink parsing for wiki inclusion ardupilot#27226
• Store those outputs somewhere for existing firmwares
  • Add initial MAVLink message files ParameterRepository#7
• Add per-vehicle dropdown version selection support, like the parameter lists
• Include in the wiki
  • Pull the files in during generation
  • Vaguely relevant to Dev: fill out mavlink interface pages #1884, although that's focused more on higher level overviews
  • Also somewhat relevant to Rover: create Rover mission command list doc #74, although the current auto-parsing is only for listing message names and the source file they're handled in / sent from

Longer term:

• Set up automatic generation per vehicle, per version
  • May be done via autotest, like for parameters
    • Moving the script to autotest could be useful for notifying of changes in MAVLink support on PRs, but is probably too much effort for now
  • Will likely get done externally, in what is currently the parameters repository
    • Extra attractive because the script requires Python ≥ 3.11, which will be easier to specify there than forcing autotest to update
    • WIP: scripts: auto-generate MAVLink messages files ParameterRepository#8
• Account for / mention preprocessor directives, where relevant
  • e.g. add a "notes" column, and include things like "message only included if firmware compiled with XXX flag"
• Include supported fields, and any definition/range specifics for the selected vehicle
  • For automatic parsing would likely require an explicit comment syntax for within the firmware source