fix(spans): Shim more fields for issue detectors

[jjbayer]

For performance issue detection, we shim the timestamp field for spans, but the detector code also accesses span.data and span.description.

[codecov]

Codecov Report

❌ Patch coverage is 83.33333% with 1 line in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...rc/sentry/spans/consumers/process_segments/shim.py	83.33%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           master   #103353      +/-   ##
===========================================
+ Coverage   80.67%    80.70%   +0.02%     
===========================================
  Files        9236      9241       +5     
  Lines      394524    394801     +277     
  Branches    25148     25148              
===========================================
+ Hits       318286    318615     +329     
+ Misses      75791     75739      -52     
  Partials      447       447