proxy: report redis broken message metric

[khanova]

Problem

Not really a problem. Improving visibility around redis communication.

Summary of changes

Added metric on the number of broken messages.

Checklist before requesting a review

• I have performed a self-review of my code.
• If it is a core feature, I have added thorough tests.
• Do we need to implement analytics? if so did you add the relevant metrics to the dashboard?
• If this PR requires public announcement, mark it with /release-notes label and add several sentences in this section.

Checklist before merging

• Do not forget to reformat commit message to not include the above checklist

[github-actions]

2484 tests run: 2359 passed, 0 failed, 125 skipped (full report)

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Code coverage* (full report)

• functions: 28.8% (6961 of 24204 functions)
• lines: 47.2% (42622 of 90225 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
251db85 at 2024-03-05T13:41:34.662Z :recycle:}