Need a way to pass partition ID in outbox Event Router [DBZ-5089]

Migrated from [DBZ-5089](https://issues.redhat.com/browse/DBZ-5089)

 
h1. Feature request or enhancement

For feature requests or enhancements, provide this information, please:
h2. Which use case/requirement will be addressed by the proposed feature?

As discussed in [https://debezium.zulipchat.com/#narrow/stream/302529-users/topic/Custom.20Partitioner,] there should be a way in Debezium Outbox Event Router to provide a Partition Id. Debezium should honor this partition id and produce a message in that particular PartitionId ( the way a normal Kafka Producer API does)
h2. Implementation ideas (optional)

Based on our thinking, this can be implemented by using a new column in Outboxevent table which can be a nullable column. If a partition id is passed then produce a message in that partitionid. 

The issue does not name implementation files, tests, or entry points. Start by locating the Debezium Outbox Event Router and its Outboxevent schema, then trace how records are sent through the Kafka Producer API; done means a nullable partition ID can be supplied and the message is produced to that partition when present.

Written by the indexing model from the issue text.