Use mid-level render APIs for render

[tychedelia]

Currently from #960, we are using a pretty direct port of the existing rendering, running everything in our own ViewNode in Bevy's render graph. However, since we're not really doing anything complex here, we should be able to use Bevy's mid-level render APIs instead. This will hopefully bring us more closely aligned with Bevy idiom's, and provide better integration for doing stuff like combining Nannou with a 3d Bevy scene.