KsqlTesterTest coverage for partition/offset

Is your feature request related to a problem? Please describe. When trying to develop tests for the new pseudocolumns ROWPARTITION and ROWOFFSET, which represent the partition and offset of the record, respectively, I found that the returned partition and offset were always equal to 0.

Describe the solution you'd like The spoofed kafka topic to include support for partition and offset- QTTs don't do this perfectly (see https://github.com/confluentinc/ksql/issues/7982) , but they provide enough support for most use cases.

Describe alternatives you've considered Adding testing without coverage for partition/offset values. This is probably fine for now but can be improved upon.