Feature request or enhancement

Which use case/requirement will be addressed by the proposed feature?

Outbox event router supports arbitrary payload formats with BinaryDataConverter as the value.converter which passes payload transparently. However this is  currently not supported with the embedded engine which handles message conversion using value.format to specify the format.

In addition, when we want to pass payload transparently, it makes sense to also pass aggregateid i.e. the event key transparently. The default outbox table configuration specifies aggregateid as a varchar which is also not supported by embedded engine.

Propose to introduce the following change to support the above use cases.

1. Support for string and binary serialization formats on debezium api.
2. Allow configuring separate key and value formats on embedded engine.