Extra double quotes on Kafka message produced by Quarkus Outbox Extension

Hi,

Notice the messages produced by outbox extension are with extra double quotes. The following is the example of the output seen in the Kafka topic. Notice the key and value are surrounded with unnecessary double quotes. I believe this is caused by serialisation of string as part of an JSON object. This will be a problem when you need to perform joins in stream where the other stream with the same key will not be matched because of this extra quotes. It also not possible to use ObjectMapperSerde to deserialise the value because of this extra quotes.

key = "1-20210930-135723165-53698", value = "{\"id\":\"1-20210930-135723165-53698\",\"recipientAccountNo\":\"1-234567-4321-9876\",\"sourceAccountNo\":\"1-987654-1234-4569\",\"amount\":100.0,\"recipientReference\":\"Payment for lunch\",\"paymentType\":\"CASA\",\"createdTimestamp\":\"2021-09-30T13:57:23.165992Z\",\"eventSources\":\"blog.braindose.opay.casa.Casa\",\"eventTimestamp\":\"2021-09-30T13:57:23.165992Z\",\"status\":\"SUBMITTED\"}"

You can workaround this with map() and custom deserialization but it will create non-standarization in dealing with kafka messages.