feat(webgpu): Ability to override render targets on RenderPipeline

[ibgreen]

For #

Background

• In WebGPU, pipelines must be created with information about which types of attachments they will be used with.
• So far we have been making assumptions but as we implement texture support this is becoming an obstacle.

Change List

• Add new parameters to RenderPipeline and implement on WebGPU
• Move the preferred*Format fields to device rather than canvas context for easier access

TODO

• Update caching to consider color targets
• Docs