Start to support Breeze style from Plasma desktop in digiKam bundles to...

Start to support Breeze style from Plasma desktop in digiKam bundles to prevent a broken rendereing of widgets and icons when breeze theme is used.
Intentional: this do not includes decoration and kcm parts, only the core libs plus theme files --> these implementations must be available as a KF5 component, not in Plasma
A KDE application ALSO work under MacOS and Windows, not ONLY Linux. As usual, reduce the puzzle please.
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