Improve the accessibility of our modals (the color picker and the export dialog)
Implement a focus trap so that tapping through the controls inside them don't escape to outer elements, it also allows to close the modals with the "Escape" key.
* Extract app component from entrypoint (index)
- Use refs to refer to canvas and rough context
- Remove ReactDOM double rendering
* Extract keys and key related utils into their own module
* Move everything back to entrypoint
