Make a browser addon visual inspector

[jo-chemla]

Inspired by aframevr-inspector discussion aframevr/aframe-inspector#597, it could be great to be able to run triplex - or a smaller-scale variant - on top of an existing threejs scene loaded in a browser tab, as an addon. aframevr-inspector can be simply invoked via a keyboard shortcut, and replaces the scene by a visual inspector with 3d objects selectable, and panels and components to edit their properties and attributes.

The addon would parse an existing threejs scene graph, build-up components, and allow interaction with the scene, eventually exporting to a standard r3f scene component graph. Possible similar issue pmndrs/gltfjsx#255 probably a lot more complex than the existing r3f-based scene parser.