Improve trace validation test experience

[joshuazh-x]

Following up on previous discussion with @serathius and @ahrtr, we aim to automate the trace validation test with random Raft traces (in normal and in fault conditions).

1. This requires a mock application to generate random Raft traces in both normal and fault conditions.
2. The test shall be easy to run both manually and integrated with GitHub actions.
3. Traces shall be kept in case of test failure so we can troubleshoot the root cause.

[joshuazh-x]

PR #204 is submitted to address the follow-ups here.

cc @serathius @ahrtr