Add a DLQ fallback to computation policy

Today the computation policy can define a retry policy and a fallback which is Stop or Drop (continueOnFailure=true).
It would be nice to be able to have an option to send the record in a Dead Letter Queue as well.
Something like this:

    <streamProcessor name="myStreamProcessor" class="org.nuxeo.runtime.stream.tests.MyStreamProcessor" logConfig="default">
      <stream name="dlq-myComputation" partition="1" />
      <policy name="myComputation" maxRetries="10" delay="1s" maxDelay="60s" continueOnFailure="true" dlqStream="dlq-myComputation" />
...
 

How to replay the records in the DQL is another story:

• a simple way can be to copy the DLQ records into the original stream so they are reprocessed, this can be done using stream.sh dump and append.
• have an option on the stream processor to start processing DLQ before input streams.
• define a new recovery processor that reads from the DLQ (like it is done on the WorkManager repair procedure NXP-27148)

Of course, for the 2 lasts options the DLQ mechanism should be disabled to not run in an infinite loop in case of systematic failure.