Use JavaFX directory chooser instead of Swing directory chooser in Swing modules

[Oliver-Loeffler]

The JavaFX directory chooser works way better than the old Swing directory chooser. Replace Swing directory chooser with JavaFX directory chooser.

Consider generalization to make both interchangeable.

[Oliver-Loeffler]

Provide Swing-Wrapper API to access the JavaFX FileChooser and Directory chooser, while keeping modality and configurability (e.g. file extensions).