Refactor property/indexer reflection for type safety & nullability

Refactored reflection infrastructure for property and indexer getters/setters:
- Removed IPropertyDataInvoker; merged logic into PropertyData.
- Updated all delegates and APIs to use nullable reference types (class?).
- Standardized parameter naming to "indices" for indexers.
- Generalized indexer support for any parameter count.
- Improved delegate caching and creation for type safety.
- Removed legacy object-based getter/setter methods.
- Enhanced documentation and error messages for clarity.
- API is now more robust, type-safe, and consistent.

Author: BionicCode