Support for new Flink Source and Sink inferfaces #3536
Description
Flink 1.11 introduced new Source and Sink instead of the SourceFunction and SinkFunction interfaces. Currently Nussknacker easily supports only old interfaces via BasicFlinkSource and BasicFlinkSink. New Flink Source and Sink can be used only while preparing custom DataStream along with low-level stuff like watermarks, operator ids, etc. using Nussknacker FlinkSource and FlinkSink. In addition, some connectors have been already switched to new the API.
More details how to implement a source using the new interface: https://nightlies.apache.org/flink/flink-docs-stable/docs/dev/datastream/sources/#data-source-concepts