Create QMLDataType base class in order to be able to use simple types defined in C++ without dependency of QObject

At the moment developers have to use QObject derived heavy objects with properies or QVariantMap with heap allocation. It seems not the most performant solution.

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C++:

class MyQMLType : public QMLDataType

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QML:

Rectangle {

property MyQMLType data: model.getData()

x: data.x

y: data.y

color: data.color

}