SQL_MAX_IDENTIFIER_LEN info type should be in characters, not in bytes.

ODBC specs explicitly say that SQL_MAX_IDENTIFIER_LEN type info is length in characters. Additional story that ODBC specs by "characters" often mean SQLWCHAR units. It's kinda have to be decided, But currently it returns bytes. for other info types - SQL_MAX_CATALOG_NAME_LEN, SQL_MAX_COLUMN_NAME_LEN, SQL_MAX_TABLE_NAME_LEN the specs say nothing. Even though it feels like it has to be in characters, we better keep it as it is now - in bytes