kwineffects: Add OffscreenQuickScene::setSource with initial properties
Split out from !2040 (merged)
It's nice API to have anyway and reduces the patch delta for the aforementioned MR.
Kai Uwe Broulik kai_uwe.broulik@mbition.io on behalf of MBition GmbH
https://github.com/mercedes-benz/daimler-foss/blob/master/PROVIDER_INFORMATION.md