Allow download button for interactive Audio and Video components (#7104)
* allow download button for interactive audio and video components
* add changeset
* document show_download_button in video.py
* ensure show_download_button is by default true for output and false for input components
* fix component test
* tweak default val
* val tweak
* fix test and add story
* pass editable param where needed
* fix another test
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Co-authored-by: gradio-pr-bot <gradio-pr-bot@users.noreply.github.com>
Co-authored-by: Dawood Khan <dawoodkhan82@gmail.com>