Allow gr.Interface.from_pipeline() and gr.load() to work within gr.Blocks()

[abidlabs]

We were prematurely rendering components when using Interface.from_pipeline() as well as using gr.load() which meant that you could not use those functions inside of a Blocks(). This fixes those issues and adds a couple of unit tests.

Fixes: #5224

Repros:

import gradio as gr
from transformers import pipeline
classifier = pipeline(task="image-classification")

with gr.Blocks() as demo:
    with gr.Tab("Image Inference"):
        gr.Interface.from_pipeline(classifier)
demo.launch()

import gradio as gr

with gr.Blocks() as demo:
    gr.load("models/google/vit-base-patch16-224")
demo.launch()

[gradio-pr-bot]

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---

Install Gradio from this PR

pip install https://gradio-builds.s3.amazonaws.com/ed4be2992c95cb86780f7f83ba18b5fc258a05f5/gradio-3.40.1-py3-none-any.whl

Install Gradio Python Client from this PR

pip install "gradio-client @ git+https://github.com/gradio-app/gradio@ed4be2992c95cb86780f7f83ba18b5fc258a05f5#subdirectory=client/python"

[gradio-pr-bot]

🦄 change detected

This Pull Request includes changes to the following packages.

Package	Version
gradio	patch

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Allow gr.Interface.from_pipeline() and gr.load() to work within gr.Blocks()

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[aliabid94]

LGTM

[freddyaboulton]

Thanks @abidlabs !

[freddyaboulton]

Let's close the demo when we're done with the test