Run before_fn and after_fn for each generator iteration

[freddyaboulton]

Description

Closes: #7020
Closes: #6762

The issue is that the after_fn which sets in_event_listener to False was never run for the iterations of an async generator. This meant the component init run this line was not working properly.

To test, you can use the repro from the original issue:

import gradio as gr
Start = False

def change():
    global Start
    print(Start)
    if Start:
        Start = False
        return gr.Button(interactive=False)
    else:
        Start = True
        return gr.Button(interactive=True)

with gr.Blocks() as demo:
    with gr.Column():
        btn0 = gr.Button("btn0", interactive=False)
    demo.load(change, None, btn0, every=1)
    demo.queue()
    demo.launch(debug=True)

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[gradio-pr-bot]

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---

Install Gradio from this PR

pip install https://gradio-builds.s3.amazonaws.com/790541bf3fb90bb09cae1fd0794b753853caee88/gradio-4.15.0-py3-none-any.whl

Install Gradio Python Client from this PR

pip install "gradio-client @ git+https://github.com/gradio-app/gradio@790541bf3fb90bb09cae1fd0794b753853caee88#subdirectory=client/python"

[gradio-pr-bot]

🦄 change detected

This Pull Request includes changes to the following packages.

Package	Version
gradio	patch

• Maintainers can select this checkbox to manually select packages to update.

With the following changelog entry.

Run before_fn and after_fn for each generator iteration

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[aliabid94]

is this ready for re-review?

[freddyaboulton]

@aliabid94 Yes !

[aliabid94]

LGTM!

[freddyaboulton]

Thanks for the review @aliabid94 !