ComponentPropertyModel is not usable with NestedComponentModel

[thrau]

Reproduce:

• Add a component child to a component parent that uses a model
• Use a NestedComponentModel for the component child to delegate the calls to the model of parent
• Add another component subchild to child using a ComponentPropertyModel to access properties of the model used by child, and subsequently parent.
• Model access throws exception

because the ComponentPropertyModel uses getInnermostModel, which in the case of a ComponentModel is not the IWrapModel that does the delegation, ComponentModel#getObject is called, which then throws an exception.