Some enhancements to gr.Examples

[abidlabs]

• Fixes: Ability to pass elem_id to Examples #2117 so that gr.Examples supports an elem_id field.

Test by running:

with gr.Blocks(css="#ex{background-color: red}") as demo:
    t = gr.Textbox()
    gr.Examples(["hi", "hello"], t, elem_id="ex")
    
demo.launch()

• Fixes: In Examples Component, if fn is provided and cache_examples=False, fn is never run #2101 by adding a run_on_click parameter to gr.Examples

Test by running:

def test(x):
    time.sleep(2)
    return "xx"

with gr.Blocks() as demo:
    t = gr.Textbox()
    o = gr.Textbox()
    ex = gr.Examples(["hi", "hello"], t, o, test, run_on_click=True)
    
demo.launch()

• Also adds documentation around rendering gr.Examples() using components that are placed later in the UI as we tend to get questions around this frequently (e.g. #2042)

[github-actions]

All the demos for this PR have been deployed at https://huggingface.co/spaces/gradio-pr-deploys/pr-2131-all-demos

[aliabid94]

LGTM

[aliabid94]

remove parentheses around (self.cache_examples)

[aliabid94]

remove blank line at start

[abidlabs]

Thanks for the review @aliabid94!

[abidlabs]

I'm going to merge this in because the flaky tests don't seem to have anything to do with Gradio, and I'm corresponding with the Spaces team to figure out what the underlying reason is