Add way to stop the the input stream when using gr.Image streaming.

[nateraw]

Is your feature request related to a problem? Please describe.
When using gr.Image for streaming like this:

import gradio as gr

gr.Interface(lambda x: x, gr.Image(source='webcam', streaming=True), "image", live=True).launch()

There is no way to stop the app from running, it just keeps going until you close the tab.

Describe the solution you'd like

It would be nice to hit a button to have the app stop streaming inputs, similar to how the audio streaming feature works.

[JefferyChiang]

#1323

[abidlabs]

Thanks for flagging the duplicate @JefferyChiang. Will close this issue and keep yours open until we can fix it!