refactor(scip): simplify Java strategy and remove relationships summary

- Refactor JavaStrategy to use simplified symbol registration methods
- Remove complex JavaAnalyzer and JavaRelationshipExtractor classes
- Simplify symbol creation with basic identifier extraction
- Remove relationships_summary calculation from SCIPSymbolAnalyzer
- Add to_scip_relationships method back to SymbolDefinition for compatibility
- Streamline Java AST processing to focus on core symbol definitions
- Remove unused relationship summary from FileAnalysis output

This change simplifies the Java SCIP strategy implementation while maintaining
core functionality for symbol definitions and basic relationships.

Author: johnhuang316

src/code_index_mcp/scip/strategies/fallback_strategy.py

@@ -347,7 +347,7 @@ def _register_symbol(self, name: str, file_path: str, descriptor: str, descripti
             symbol_id=symbol_id,
             file_path=file_path,
             definition_range=dummy_range,
-            symbol_kind=scip_pb2.UnspecifiedKind,
+            symbol_kind=scip_pb2.UnspecifiedSymbolKind,
             display_name=name,
             documentation=[description]
         )