tests: hide cumulocity iot token message from the test log output

[reubenmiller]

Proposed changes

system test improvement which hides the c8y/s/dat message payload from the log output so that the reports can be published to github issues to assist with debugging of flaky system tests.

Note: the implementation is not ideal as it is fairly fragile in nature as the mqtt messages use journald to provide time bases querying...however this introduces some complexity in parsing the log entries. Most likely a different way to handle this will be required in the future.

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	52m7.851999999s

[didier-wenzek]

Approved