tests: include more readable mqtt logs in Get Logs keyword

[reubenmiller]

Proposed changes

Include a more readable version of the mqtt messages received during a system test by including a separate mqtt log output section in the Robot Framework Get Logs keyword.

The benefits are:

• Easier to read and see errors by only including the timestamp, topic and message (don't included any additional meta information that is store in the mqtt-logger output, .e.g. hex into.)

The same detailed information is still provided within the journald output (to see the interactions of the mqtt messages with the service log entries), however the messages are more difficult to read and isolate from the log entries for cases where the tester only cares about the mqtt messages being sent.

Example

The logs can easily be copied/pasted from the system test report for detailed analysis.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (general improvements like code refactoring that doesn't explicitly fix a bug or add any new functionality)
• Documentation Update (if none of the other choices apply)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Paste Link to the issue

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA (in all commits with git commit -s)
• I ran cargo fmt as mentioned in CODING_GUIDELINES
• I used cargo clippy as mentioned in CODING_GUIDELINES
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

[github-actions]

Robot Results

✅ Passed	❌ Failed	⏭️ Skipped	Total	Pass %	⏱️ Duration
356	0	3	356	100	58m49.242999999s

[albinsuresh]

LGTM except for that error handling risk. Of course, the damage would be minimal as this is typically part of the tear down process.