Draft: tools: add libinput analyze-device

The eventual goal of this tool is for it to be a self-help tool - a user can run this tool and it will point out things that are missing or just unexpected.

Fixes #779

cc @JoseExposito - after a few false starts I'm finally happy with the approach (notably the Check/Result split). Formatting could need some attention and of course there are other bits missing (e.g. libinput data itself). But hey, it's a first draft...