Automatic AABBs for render types

Render types:
- VelloScene
- VelloSvg
- VelloLottie
- VelloText

All should have automated AABBs added on creation.

Currently we cannot do this automatically due to limitations of the Vello API.
See: https://xi.zulipchat.com/#narrow/channel/197075-vello/topic/Scene.20BB/with/520480143 

Current implementation: 
- [ ] VelloScene
- [x] VelloSvg
- [x] VelloLottie
- [ ] VelloText

