refactor transaction manager, MVCC execution, WAL, locking, and savepoint handling, and SQL parsing.

Implement transaction management with autocommit and isolation level support

Implement ORDER BY functionality with support for multiple columns and complex sorting logic

Refactor SQL column parsing to support complex function names Created `OrderByClause` for parsing ORDER BY clauses, including support for multiple columns and default ascending order.

Enhance full-text search tests by verifying expected article titles and ranking logic

use new format

introduce QueryResult and ColumnInfo structures

Introduced built-in functions for full-text search: `to_tsvector`, `to_tsquery`, and `ts_rank`.

Add functions module with built-in functions and registry

Refactor SQL module to introduce ColumnType and TableReference structs, enhancing column management and parsing logic

Refactor SQL handling by introducing TableReference struct for improved table management in SELECT statements and JOIN clauses. Update related parsing logic and tests to accommodate the new structure.

Added support for new data types: BOOLEAN, FLOAT, DATE, TIMESTAMP, and NULL

Refactor full-text search module by adding ranking support and updating imports for FTSClause.

Refactor full-text search parsing logic and introduce new components

Introduced a new QueryEvaluator struct to handle complex query evaluations, including AND, OR, NOT, phrase, and proximity searches.