[Backport 7.59.x] [postgres] Fix unicode decode error from Azure PostgreSQL Flexible Server

[datadog-agent-integrations-bot[bot]]

Backport 3d527cab62aa44313d690f64b8ee569ed1f0dc7f from #18938.

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What does this PR do?

This PR fixes the bug encountered in Azure PostgreSQL Flexible Server in the backend_type column of pg_stat_activity.

There is a bug on Microsoft's side where they send a non valid utf-8 string in that column, leading to decoding errors when trying to fetch this column.

The workaround is to query that same column with ::byteasuffix to convert the field into bytes then parsing backend_type manually. The bug still exists but now we just handle those error cases instead of failing on the whole query.

Motivation

https://datadoghq.atlassian.net/browse/SDBM-1169 https://datadoghq.atlassian.net/browse/SDBM-1197

incident-31599

A couple of customers where seeing errors utilizing DBM with Azure PG Flexible Server when agent tries to query backend_type from pg_stat_activity. We previously issued a fix but had to revert due to many warnings being logged from the agent.

Review checklist (to be filled by reviewers)

• [ ] Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• [ ] Add the qa/skip-qa label if the PR doesn't need to be tested during QA.
• [ ] If you need to backport this PR to another branch, you can add the backport/<branch-name> label to the PR and it will automatically open a backport PR once this one is merged

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 77.77778% with 2 lines in your changes missing coverage. Please review.

Please upload report for BASE (7.59.x@cff91ad). Learn more about missing BASE report.

Additional details and impacted files

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