Align traceparent with Sentry's sentry-trace header

[jamescrowley]

The span id within transparent will not match, but the trace id itself will. Can review if/when Sentry support for traceparent getsentry/sentry-javascript#11171 (comment) progresses.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 83.93%. Comparing base (ef23ce8) to head (0d5e64f).
Report is 11 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1639      +/-   ##
==========================================
- Coverage   84.11%   83.93%   -0.18%     
==========================================
  Files         232      232              
  Lines       14343    14373      +30     
  Branches     1511     1511              
==========================================
  Hits        12064    12064              
- Misses       2240     2270      +30     
  Partials       39       39              

Flag	Coverage Δ
backend	99.03% <ø> (ø)
frontend	77.59% <ø> (-0.24%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

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

[jamescrowley]

@pylipp @HaGuesto confirmed this works in staging. traceid aligned between sentry/gcp. The span id does not, as sentry still does it's own thing wrapping requests, but I think this will do us for now until Sentry supports direct integration.

[pylipp]

2.0: Align traceparent with Sentry's sentry-trace header