Allow to create valid KPluginMetaData for plugins without embedded JSON metadata
Currently one can not allow plugins to have empty JSON metadata, without having them considered invalid.
However we have usecases where we want to load a plugin without having to embed json metadata, for example a KCM in a KPluginWidget, a KPart in Kontacts by name or an Plasma Applet where we have the metadata in KPackage available.
Edited by Alexander Lohnau