JavaFX: Single-Control view (Use case).
- Adjust the FX playground classes to the AF3FXViewPart changes in the kernel.
- Modify the "FXNavigator" to provide a use case for single-control/node views.
Issue-Ref: 3463 Issue-Url: https://af3-developer.fortiss.org/issues/3463 Signed-off-by: Alexander Diewald diewald@fortiss.org