Feature request or enhancement

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

The new single message transform (SMT) ExtractChangedRecordState delivers the information which values have changed in a Debezium change event by adding relevant metadata to the event.

To make easy use of this feature in the downstream processing of the events, it would be necessary to have the information what values have changed optimally in a metadata field of the payload. An example could look like as follows:

... 
"before":   
 { "ID": 1004, "FIRST_NAME": "Anne", "LAST_NAME": "Kretchmar" },
"after": 
 { "ID": 1004, "FIRST_NAME": "Maria", "LAST_NAME": "Kretchmar" },
"changed_fields": { "FIRST_NAME" },
...