stats/opentelemetry: CSM Observability server side component changes

[zasweq]

This PR adds the CSM Observability logic for the client side of the OpenTelemetry component.

Also contains #7256. The second commit is the scope of this PR.

RELEASE NOTES: N/A

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.61%. Comparing base (adf976b) to head (3144bc6).
Report is 65 commits behind head on master.

❗ Current head 3144bc6 differs from pull request most recent head 0a11503

Please upload reports for the commit 0a11503 to get more accurate results.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #7257      +/-   ##
==========================================
- Coverage   81.24%   80.61%   -0.63%     
==========================================
  Files         345      349       +4     
  Lines       33941    33993      +52     
==========================================
- Hits        27574    27404     -170     
- Misses       5202     5408     +206     
- Partials     1165     1181      +16     

see 43 files with indirect coverage changes