* Filter Dialog: added initial version of FXML layout.
* Filter Dialog: fixes in FXML layout.
* Filter Dialog: added initial version of FilterDialogController and FilterViewModel.
* Filter Dialog: completed FilterViewModel implementation and added unit tests.
* TODO updates.
* Filter Dialog:
  * setup of binding and validation.
  * added event handler for date selection.
* Filter Dialog: added choicebox setup and event handling.
* Filter Dialog: added selection for intensities, including "all" (uses new wrapper class IntensityItem).
* Filter Dialog: completed controller implementation and manual testing.