Change setIcons method

We currently have this: https://github.com/Parabot/Internal-API/blob/master/src/main/java/org/parabot/api/ui/SwingUtil.java#L29

This should be changed to: https://github.com/Parabot/Parabot/blob/feature/release-3.0.0-RC-01-ui/src/main/java/org/parabot/core/ui/newui/BotUI.java#L39

Make sure to create a new class for this, as this isn't Swing anymore, but JavaFX