Implement environment data

[jorisvddonk]

onboard devices -> miscellaneous -> environment data

Shows external environment info:

Somewhat annoyingly, original behaviour is that ESCAPE closes this, and the closing of this has priority over cancelling setting remote target, setting local target, or deploying surface capsule. In practice, that means that it's quite common to accidentally end up closing this screen (and any other data screens). I'd suggest not replicating that behaviour, and instead have it close when you disable the screen again from the FCD.