KIP-307 — Allow to define custom processor names with KStreams DSL

Accepted Kafka 2.3 Streams

Adds a `NamedOperation` interface with an `as(String)` factory on the Kafka Streams DSL control classes (`Produced`, `Consumed`, `Printed`, `Joined`, `Grouped`, `Suppressed`) plus overloads on the stateless operators, so every processor in a topology can be given a custom name. Processor names are otherwise generated from the operation type with a uniqueness suffix (`KSTREAM-MAP-0000000000`), which makes the `Topology#describe()` lineage of a topology with dozens of operations hard to read.

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