[Client] Fix two bugs in MonitoredItem

[tobiasfrick]

Proposed changes

This PR fixes two bugs in the client-side MonitoredItem implementation and adds some unit tests.

1. There was a bug in the MonitoredItemDataCache.Publish method: the for loop was never executed since values.Count was always empty. This means that for MonitoredItems where CacheQueueSize is >1, DequeueValues() always returned an empty list.

2. I noticed that CacheQueueSize was not serialized / deserialized.
   I added it to the MonitoredItemState record and changed the data type to uint.
   I'm not sure if this was intentionally omitted from serialization, if there is a reason for it I can undo the changes ...

Related Issues

Types of changes

What types of changes does your code introduce?
Put an x in the boxes that apply. You can also fill these out after creating the PR.

• Bugfix (non-breaking change which fixes an issue)
• Enhancement (non-breaking change which adds functionality)
• Test enhancement (non-breaking change to increase test coverage)
• Breaking change (fix or feature that would cause existing functionality to not work as expected, requires version increase of Nuget packages)
• Documentation Update (if none of the other choices apply)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your code.

• I have read the CONTRIBUTING doc.
• I have signed the CLA.
• I ran tests locally with my changes, all passed.
• I fixed all failing tests in the CI pipelines.
• I fixed all introduced issues with CodeQL and LGTM.
• I have added tests that prove my fix is effective or that my feature works and increased code coverage.
• I have added necessary documentation (if appropriate).
• Any dependent changes have been merged and published in downstream modules.

Further comments

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 60.19%. Comparing base (d25caff) to head (c9d6525).
⚠️ Report is 76 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3447      +/-   ##
==========================================
+ Coverage   51.86%   60.19%   +8.32%     
==========================================
  Files         370      377       +7     
  Lines       78618    78645      +27     
  Branches    13650    13710      +60     
==========================================
+ Hits        40779    47340    +6561     
+ Misses      33705    26949    -6756     
- Partials     4134     4356     +222     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[romanett]

Thank you for providing these fixes

[romanett]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).