Migrate gr.MultimodalTextbox (#12789)
* refactor mmtextbox
* add changeset
* add changeset
* tweaks
* format
* remove unused props
* remove unused props
* fixes
* fix
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Co-authored-by: gradio-pr-bot <gradio-pr-bot@users.noreply.github.com>
Co-authored-by: Freddy Boulton <41651716+freddyaboulton@users.noreply.github.com>
