Clean D&D tooltip dialog

As **developer** I want to clean D&D tooltip dialog class **so that** I can use the current icon application

**Acceptance Criteria**
- [DragTooltipDialog](https://github.com/josdem/jmetadata/blob/main/src/main/java/com/josdem/jmetadata/dnd/DragTooltipDialog.java) has only tracks icon type
- I can see unused methods deleted
- I can see Java 21 version applied to the class
- All test passing