wire up available locales correctly

Dropped incorrect button-disables, added relevant listener
Fixes #50

Author: Vogel612

src/main/java/de/vogel612/helper/ui/jfx/JFXFilesetOverviewView.java

@@ -61,6 +61,7 @@ public JFXFilesetOverviewView(LocaleChooser localeChooser, FilesetOverviewModel
         controller.addSaveRequestListener(this::onSaveRequest);
         controller.addTranslationRequestListener(this::onTranslateRequest);
         controller.addFileRequestListener(this::onFileRequest);
+        controller.addLangChoiceListener(this::selectLocale);
     }
 
     @Override

src/main/java/de/vogel612/helper/ui/jfx/JFXLocaleChooserController.java

@@ -61,6 +61,8 @@ private void showLocaleDialog(Consumer<String> callback) {
     public void updateAvailableLocales(final Collection<String> locales) {
         localeOptionCache.clear();
         localeOptionCache.addAll(locales);
+        leftTranslation.setText("(none)");
+        rightTranslation.setText("(none)");
     }
 
     @Override
@@ -71,8 +73,6 @@ public void initialize(URL url, ResourceBundle resourceBundle) {
         Objects.requireNonNull(rightChoose, "rightChoose was not correctly FXML-injected");
         Objects.requireNonNull(submit, "submit was not correctly FXML-injected");
 
-        leftChoose.setDisable(true);
-        rightChoose.setDisable(true);
         submit.setOnAction(evt -> completeChoice());
         leftChoose.setOnAction(evt -> showLocaleDialog(result -> {
             left = result;