Addon Refactoring: Singleton and Static Method for Unregister

[ArceDanielShok]

This Pull Request introduces two main changes to improve the management and consistency of the addon: the creation of a singleton for the addon and the conversion of the unregister method to static.

• Creation of a singleton for the addon:
  • A singleton pattern has been implemented for the addon. This ensures that only one instance of the addon exists throughout the application, facilitating state management and preventing potential conflicts.
• Conversion of the unregister method to static:
  • The unregister method, which used provider id for deregistration, has been converted to a static method. This allows for more direct and consistent access to the method, without the need for an addon instance.