Refactor showPasswordProperty listener in EnhancedPasswordField

Switched the listener on showPasswordProperty to a subscribe method in the 'EnhancedPasswordField' class. This change promotes cleaner code structure and improves the readability of the EnhancedPasswordField component's code.

gemsfx/src/main/java/com/dlsc/gemsfx/EnhancedPasswordField.java

@@ -64,7 +64,8 @@ public class EnhancedPasswordField extends PasswordField {
     public EnhancedPasswordField() {
         super();
         getStyleClass().add(DEFAULT_STYLE_CLASS);
-        showPasswordProperty().addListener(it -> pseudoClassStateChanged(SHOWING_PSEUDO_CLASS, isShowPassword()));
+
+        showPasswordProperty().subscribe(showing -> pseudoClassStateChanged(SHOWING_PSEUDO_CLASS, showing));
 
         //set right node
         FontIcon fontIcon = new FontIcon();