qmltc: support custom parser types

(Splitted from QTBUG-91956)

Test and support common custom parser types (Andrei does not think that one could support generic custom parser types).

• (need to figure whether these should be supported at all - QTBUG-95117)
• QQmlListModel (QML ListModel)
• QQmlConnections (QML Connections)
• QQuickPropertyChanges (QML PropertyChanges)
• SignalTransition