Improve quickchoice width

[romcode]

Hi,

Setting quickchoice component width in pixels leads to poor user interface depending of the widht of the device.

Setting the width in percentaje or when the component is inside the new Section (Pilot) filling the full width available, would allow a better UI experience.

Thank you very much for your great effort.

[romcode]

FYI: I've checked by my side that putting the width to a high value (e.g. 9999 pixels) the component renders filling all available space (like it has 100% width).

This works fine, at least in Windows Chrome and Salesforce Mobile App iOS.