proxy: Record role to span

[khanova]

Problem

Summary of changes

Add dbrole to span.

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]

2760 tests run: 2642 passed, 0 failed, 118 skipped (full report)

---

Code coverage* (full report)

• functions: 27.9% (6398 of 22958 functions)
• lines: 46.4% (44742 of 96518 lines)

* collected from Rust tests only

---

_{The comment gets automatically updated with the latest test results
50d0a43 at 2024-04-17T12:21:09.005Z :recycle:}