Luma API update, animometer example revisited

[ilijapuaca]

• Revisited some of the API in Model/AnimationLoop
• animometer example now uses the updated API instead of making calls to dawn API directly
• Minor dependency cleanup

Few things worth noting:

• There seems to be a memory leak in the run loop (it's there even in example provided by dawn, without any modifications)
• Most of the WebGPU objects are being passed around by value across the API. This initially seemed weird to me so I started trying to turn them into pointers, which makes the function calls somewhat sloppy. Any particular reason they are being passed by value, are they that lightweight? I assumed that making copies of these was causing the memory leak, based on this text from WebGPU spec:

WebGPU sees physical GPU hardware as GPUAdapters. It provides a connection to an adapter via GPUDevice, which manages resources...

• Did we give threading some thought when it comes to rendering?

[ilijapuaca]

Landing this together with #92, will address any comments as they come