TV and VR device icons needed

[ryanfeeley]

Just like we have small and large phone, tablet and laptop icons (below), we need TV and VR icons for the next generation of FxA devices.

Related:
mozilla/fxa#1856 (comment)

[nt1m]

There is a VR icon: https://design.firefox.com/icons/viewer/#web%20vr

[nt1m]

Looks like a TV icon landed on mozilla-central but wasn't added to the repo:
https://searchfox.org/mozilla-central/source/browser/themes/shared/icons/device-tv.svg

There's also a add-device icon to add to this repo:
https://searchfox.org/mozilla-central/source/browser/themes/shared/fxa/add-device.svg