Connectors should not depend on `flink-table-planner`

Connector modules currently rely heavily on `flink-table-planner` as a test dependency for testing the ITCases with 'DynamicTableX' using the TableFactory to load the respective connector. 

There is now a better way that only requires to have `flink-table-test-utils` as a test dependency. Therefore all connectors should be migrated to using the new way.