core: Add unit test for LogEventSerializer

[haiqi96]

References

Description

Added unit test for LogEventSerializer and Deserializer

The unit test does the following:

1. Encode two log events into an IR file
2. Decodes the two log events from the IR file and convert them to plain text log message
3. Verify that the encoded log_events and decoded log events are identical

Validation performed

New test is added to the unit test and passed