[WIP] Add /instruments page to Companion

[Williangalvani]

This is just reviving the work I did some time ago for use with OBS Studio. This provides a webpage that can be used in OBS Studio as an overlay for the video. It has two default instruments and a menu to select other mavlink data.

The idea of this PR is basically showcasing what can be done, the UI needs some work before it is good.

example (used a recorded video, doesnt match attitude): https://youtu.be/EdI1ghTIX30