Redesign `gr.Button()` (#9167)
* *add new button styling
*add origin theme class with old button styling
* add changeset
* remove new colour
* add changeset
* color and radius tweaks
* remove neutral hue change
* *update button demo
*style tweaks
* format
* fix test
* use white text on primary btn
* adjust primary orange
* tweak colour
* disabled fixes
* refactor
* refactor
* refactor
* refactor
* remove non-button changes
* test
* revert test
* make cancel btn darker in light mode
* change button stories to interactive
* fix slider test
* fix test
* tweak
* tweak secondary colour to work with gr.group()
* add changeset
* tweak
* tweak button hover grey
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Co-authored-by: gradio-pr-bot <gradio-pr-bot@users.noreply.github.com>
Co-authored-by: pngwn <hello@pngwn.io>
