Fixes #2060. ComboBox is duplicating subviews and mouse move not work by open another ComboBox.

[BDisp]

Fixes #2060 - The constructor that has the source parameter use now his own initialization and I replaced the wrong property WantContinuousButtonPressed by WantMousePositionReports. I also added a new combo box into the ComboBoxIteration.cs scenario to visually test the mouse move when opening more than once combo box's.

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