Refactor mount helpers and expose NPC flight state

src/main/java/noppes/npcs/controllers/data/PlayerData.java

@@ -84,6 +84,7 @@ public class PlayerData implements IExtendedEntityProperties, IPlayerData {
     public ScreenSize screenSize = new ScreenSize(-1, -1);
 
     public int profileSlot = 0;
+    private boolean specialKeyDown = false;
 
     public void onLogin() {
         // Continue playing animation for self when re-logging
@@ -267,6 +268,14 @@ public class PlayerData implements IExtendedEntityProperties, IPlayerData {
         return this.isGUIOpen;
     }
 
+    public boolean isSpecialKeyDown() {
+        return specialKeyDown;
+    }
+
+    public void setSpecialKeyDown(boolean specialKeyDown) {
+        this.specialKeyDown = specialKeyDown;
+    }
+
     public ScreenSize getScreenSize() {
         return screenSize;
     }