Implement Java OOP Pattern Analysis

- Enhanced field access analysis with proper encapsulation detection
- Implemented comprehensive getter/setter pattern analysis
- Added data hiding score calculation based on encapsulation quality
- Implemented immutability pattern analysis with builder pattern detection
- Enhanced SOLID principles evaluation with real analysis instead of hardcoded scores
- Added SOLID violations detection with specific recommendations

Addresses Java Object-Oriented Pattern Analysis requirements from Milestone 3.
This implementation significantly expands Java analysis capabilities from stub methods to functional OOP analysis.

closes #76

Author: milliondreams