Replaced std::nullptr_t for boost::variant2::monostate in values
Added support for relational operators in value
Automatic docs generation
closes#48closes#46
Added a feature in meta_validator to prevent validation of certain flags
Removed validation of is_signed for TIMESTAMP and DATETIME types, as
MariaDB and MySQL return different things and is not of any use
Now examples and tests compile with more strict warning levels
Now warnings are treated like errors
Now test has its own CMakeLists.txt
Solved several warnings