Add icon and link params to `gr.Button` (#5080)
* add icons and link params
* tweak
* add changeset
* prepend icon param with /file=
* prepend icon with /file=
* restore and add button stories
* add changeset
* param description tweak
* tweak param description
* type tweak
* fix i18n in story
* fix formatting
* fix test
* tweak
* fix typo
* fix icon bug
* fix inconsistent width
* remove <a /> target
* styling changes + add story
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Co-authored-by: gradio-pr-bot <gradio-pr-bot@users.noreply.github.com>
