Display Configuration Settings UI

[killua99]

Display Configuration need an UI to override values.

Now my yml file show this.

display_configuration: widget_ids: 735d146c-a4b2-4327-a057-d109e0905e05: 'Upload files' a4ad947c-9669-497c-9988-24351955a02f: 'Files listing' width: 80 height: 550 link_text: 'Select files' auto_open: true

What I like is the width to be width: '80%' I'm using the modal widget.

[slashrsm]

I think we should change those fields from numerical to strings to allow that.