feat: Implementei a estrutura de dados da tabela de simbolos

[Bappoz]

This pull request introduces significant improvements to the parser and semantic analysis infrastructure, with a focus on handling sizeof expressions, type casting, and introducing a robust symbol table for semantic checks. It also adds comprehensive tests to ensure correctness of parsing, symbol table behavior, and special character handling. The main changes are grouped below

Parser and AST Enhancements

• Added a new Expr::SizeofType(QualifierType, Span) variant to the AST to distinguish between sizeof(type) and sizeof(expr), and updated the parser logic to correctly parse both forms.
• Removed unnecessary expression terminator checks in the parser, simplifying expression parsing and error handling.

Symbol Table and Semantic Analysis

• Introduced a symbol_table module implementing a scoped symbol table with support for declaration, lookup, shadowing, and redeclaration error detection.
• Extended SemanticErrorKind with a Redeclaration variant and improved error reporting for redeclaration cases.

Testing Improvements

• Added comprehensive tests for the symbol table, covering lookups, shadowing, redeclaration, scope management, and qualifiers.
• Enhanced parser tests to verify correct parsing of cast expressions, sizeof in both forms, and binary operations following these constructs.
• Added new tests for UTF-8 character boundary handling and memory-mapped file source input.

[Bappoz]

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