Use uppercase "KDAV" name as qmake identifier, to match KF standards
While a config interface break, I doubt that anyone currently uses KDAV via qmake, otherwise they would have noticed the non-existing include path and missing KCoreAddons dependency.
So in this case I would just ignore trying to be backward-compatible.
And actually fulfills the name as announced in the API dox, see https://invent.kde.org/frameworks/kdav/-/blob/master/metainfo.yaml#L12
Edited by Friedrich W. H. Kossebau