D10247: Add a width ratio to the OverlaySheet

[Igor Cota]

icota added a reviewer: Kirigami.

REPOSITORY
  R169 Kirigami

REVISION DETAIL
  https://phabricator.kde.org/D10247

To: icota, #kirigami
Cc: plasma-devel, apol, davidedmundson, mart, hein