handle selected_index prop change for gallery

[pngwn]

Description

Closes #6276.

This is a tricky one. This is a quick fix for gr.Gallery but we may have a similar issues for other components. This is an architectural issue really. We don't keep track of every prop change at the top level.

I'll look into a more comprehensive fix shortly.

Edit: opened an issue for the root problem (#6278)

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Install Gradio from this PR

pip install https://gradio-builds.s3.amazonaws.com/1d7bf85013b677592aac12f9209fd85e7ba7f7bd/gradio-4.0.2-py3-none-any.whl

Install Gradio Python Client from this PR

pip install "gradio-client @ git+https://github.com/gradio-app/gradio@1d7bf85013b677592aac12f9209fd85e7ba7f7bd#subdirectory=client/python"

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🦄 change detected

This Pull Request includes changes to the following packages.

Package	Version
@gradio/gallery	patch
gradio	patch

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handle selected_index prop change for gallery

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[freddyaboulton]

Confirmed the fix @pngwn thanks! End to end test? 😄

[pngwn]

Hard to test because the fix only changes styling. I'll figure out some tests when I look at the real fix.

[zixaphir]

Hello! I am a bit confused by this solution. Is this creating a new Gradio.Gallery object and feeding its selected_index property to an existing Gradio.Gallery object? Would it be possible to pass selected_index property to a Gradio.Gallery.update call instead?