Fix gr.load for file-based Spaces

[abidlabs]

There were two separate issues going on:

1. We weren't handling URLs correctly in the Client. In particular, we would transform any string that was a valid URL to a dictionary consisting of a path regardless of whether the value corresponded to a file-based component. Now, we check to see if the component is a file-based component. This is still not totally robust, as we should actually inspect the typing information to see which part of the payload is actually the file, but getting that working is a bit tricky. For now, this should be a good enough solution and I've created a new issue to track. To skip conversion, one can still set serialize=False.

2. When we loaded a Space using gr.load() and that Space had output files, we were unnecessarily copying them locally and serving the local files. This is not only inefficient but also doesn't work well with some components after the normalize_files refactor. Now we simply serve the files directly from the remote Space using the /proxy route if deserialize=False, which is a new parameter in Client (I considered other ways to implement this, including changing the behavior of serialize to cover this, but all led to other side effects or breaking changes).

Closes: #6744

The original Space doesn't have a repro but you can try this:

import gradio as gr

gr.load("gradio-tests/space_with_files_v4_sse_v2", src="spaces").launch()

I also tested this with a private version of the same Space, but it'd be great to test with a few other Spaces to make sure gr.load() is working as expected.

[gradio-pr-bot]

🪼 branch checks and previews

•	Name	Status	URL
	Spaces	ready!	Spaces preview
	Website	ready!	Website preview
🦄	Changes	detected!	Details

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Install Gradio from this PR

pip install https://gradio-builds.s3.amazonaws.com/fa3d844abf06eabc283de322b13161c651b120ac/gradio-4.17.0-py3-none-any.whl

Install Gradio Python Client from this PR

pip install "gradio-client @ git+https://github.com/gradio-app/gradio@fa3d844abf06eabc283de322b13161c651b120ac#subdirectory=client/python"

[gradio-pr-bot]

🦄 change detected

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gradio	patch
gradio_client	patch

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Fix gr.load for file-based Spaces

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[freddyaboulton]

Nice clean up and fix @abidlabs !

[freddyaboulton]

Should we call this download_files?

[abidlabs]

Yeah I agree that's a more intuitive name. I'll rename serialize to download_files as well (and soft-deprecate serialize)

[abidlabs]

Made the change @freddyaboulton, will merge in after CI