ref(contexts): Use newly added computed contexts

[iambriccardo]

This PR uses the new computed contexts fields that were added in Relay in getsentry/relay#4239.

Needs: getsentry/relay#4239

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #80579      +/-   ##
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+ Coverage   78.36%   78.41%   +0.04%     
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  Files        7206     7221      +15     
  Lines      318720   319746    +1026     
  Branches    43905    44010     +105     
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+ Hits       249771   250727     +956     
- Misses      62589    62635      +46     
- Partials     6360     6384      +24     

[jan-auer]

For a follow-up: Unless there's other dependencies on processed data, these tags could even be extracted in Relay to remove all of the logic here and centralize tag extraction in normalization.