feat: Add first class Image support for PIL images

[tssweeney]

Image Support!

@weave.op
def make_image() -> Image.Image:
    return Image.new("RGB", (512, 512), "purple")

This PR adds first class support for PIL images by leveraging the CustomWeaveType pattern. The majority of this PR are tests & improvements to the UI dispatch system such that changes like this will be easier in the future (think Audio/Video/etc..). After this PR, Images (and any custom type) now work in:

• Call I/O
  • Inputs
  • Outputs
• Objects
  • Entire Objects (Direct Publish)
  • Object Properties
  • Table Cells (Pending general table fix)

Everything works as plain data or saved refs.

And the UI has support for viewing images in:

1. Calls Table
2. Call Detail View
3. Eval Compare Page
4. Object Detail View
5. Object List View (Properties)
6. Dataset Table View (Columns)

As an additional component of this PR, I implemented Dataset Tables supporting having their rows properly serialized.

Followups:

• Lightbox / downloading of images
• Should make file/content a GET request that returns files that can be cached - rather than building blobs

[circle-job-mirror[bot]]

Preview this PR with FeatureBee: https://beta.wandb.ai/?betaVersion=f9b235350aa9a53d08917d33ff6d999b799e4d0e