In my scene, We need to specify databases that are excluded to synchronize to doris, like some databases store temporary table. Since #17803 introduce `specified_database_list` to specify 'include databases', this pr introduce new config `exclude_database_list` to specify 'exclude databases', and rename `specified_database_list` to `include_database_list` for naming symmetry. BTW, when `include_database_list` and `exclude_database_list` specify overlapping databases, `exclude_database_list` would take effect with higher privilege over `include_database_list`.