Revamp interpolator

[Segfaultd]

This PR modernizes and improves the Interpolator class implementation while maintaining
its core functionality. The changes focus on code organization, maintainability,
and type safety.

Key changes:

• Introduced template-based design to reduce code duplication
• Added dedicated interpolation policies for vec3, quaternion, and scalar types
• Improved error handling with assertions for invalid parameters
• Updated method names to follow consistent camelCase convention
• Enhanced numerical stability for floating-point comparisons
• Added proper const-correctness throughout the codebase

Performance improvements:

• Reduced unnecessary normalizations in quaternion operations
• Improved memory layout and value semantics
• Added snap threshold optimization for small movements

Test suite has been updated to reflect the new API while maintaining
full coverage of the original functionality. All tests pass with
the same expected values.

No breaking changes to existing behavior or public API functionality.