feat: add test with example trace

[smanilov]

This test gives a concrete example of how the structures can be put together to represent the execution of a program. The actual logic that is tested is contrived: it's just checkinging that the serialized message is of a certain length, but this could be flaky, as it depends on the behavior of the serde dependency.

[alehander92]

pending on further changes in the lib: we can use the new trace generation api(or a trace generated by program)
for generating such a test, or move it in the backend if needed