Implement HIR (High Intermediate Representation) Dumping and Symbol Management

• Added dump.rs to provide functionality for dumping HIR structures to a string representation.
• Introduced lib.rs to organize HIR module exports, including builder, dump, symbol, tree, and types.
• Created symbol.rs to manage symbol definitions, including Symbol, SymbolKind, and SymbolTable.
• Developed tree.rs to define HIR structures such as HirProgram, HirFunction, and HirStmt.
• Implemented types.rs to define scalar types, HIR types, value types, and array types.
• Updated lib.rs to include HIR compilation and dumping functions.
• Added tests in hir.rs to validate HIR dumping and symbol resolution, including edge cases and error handling.