Merge branch 'extra-network-preview-lazyload' of https://github.com/missionfloyd/stable-diffusion-webui into extra-network-preview-lazyload

convert to python v3.9

loopback.py Colab compatibility and bug fix

Fix notifications not triggering

This code (suggested by @abvgdeabvgde2 ) literally does the same thing and it does not break with Python 3.9, making it helpful for Google Colab users (me included).
fixes #8927
Also a partial fix for #8902 but it does not resolve the unresponsive UI problem faced by @Archon332

fix overriding getElementById on document

Add search textbox to filter available extensions by name/description

make launch.py use the same command line argument parser as the main program

disable pil checks

allow usage of latest pytorch_lighning

Updating safetensors version (fully backward compatible)

Custom height and width settings for Extra Networks cards

api error handler

fix output-html text overflow.

preserve privacy by disabling gradio analytics globally

Fix img2img-alternative-test script for SD v2.x

Don't bubble when metadata_button is clicked