Example(Internal) - NPC Viewer tracking

[ItsNature]

Overview

Description:
Implement NPC viewer tracking in the internal NPC plugin; emotes are only sent to players that can see it.

---

Review Request Checklist

• Your code follows the style guidelines of this project.
• I have performed a self-review of my code.
• I have tested this change myself. (If applicable)
• I have made corresponding changes to the documentation. (If applicable)
• The branch name follows the projects naming conventions. (e.g. feature/add-module & bugfix/fix-issue)

---