Track peak memory usage in root span metrics

[bwoebi]

Fixes #2832.

Adding php.memory.peak_usage_bytes and php.memory.peak_real_usage_bytes metrics.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.49%. Comparing base (735db41) to head (56a99ab).
Report is 3 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #2840      +/-   ##
============================================
- Coverage     81.10%   78.49%   -2.62%     
  Complexity     2516     2516              
============================================
  Files           146      173      +27     
  Lines         14651    18680    +4029     
  Branches          0      975     +975     
============================================
+ Hits          11883    14662    +2779     
- Misses         2768     3481     +713     
- Partials          0      537     +537     

Flag	Coverage Δ
appsec-extension	69.12% <ø> (?)
tracer-extension	78.17% <ø> (ø)
tracer-php	82.27% <ø> (-0.06%)	⬇️

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

see 28 files with indirect coverage changes

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 735db41...56a99ab. Read the comment docs.

[PROFeNoM]

Thanks for the quick addition :-)

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-09-06 13:20:51

Comparing candidate commit 56a99ab in PR branch bob/peak_mem with baseline commit 735db41 in branch master.

Found 4 performance improvements and 4 performance regressions! Performance is the same for 170 metrics, 0 unstable metrics.

scenario:ComposerTelemetryBench/benchTelemetryParsing-opcache

• 🟥 execution_time [+1.147µs; +3.253µs] or [+2.139%; +6.070%]

scenario:ContextPropagationBench/benchExtractHeaders128Bit-opcache

• 🟩 execution_time [-60.041ns; -27.959ns] or [-5.668%; -2.639%]

scenario:MessagePackSerializationBench/benchMessagePackSerialization

• 🟩 execution_time [-12.195µs; -9.665µs] or [-7.776%; -6.163%]

scenario:MessagePackSerializationBench/benchMessagePackSerialization-opcache

• 🟩 execution_time [-11.541µs; -7.459µs] or [-7.422%; -4.797%]

scenario:PDOBench/benchPDOBaseline-opcache

• 🟥 execution_time [+15.357µs; +18.117µs] or [+9.145%; +10.789%]

scenario:PDOBench/benchPDOOverhead-opcache

• 🟥 execution_time [+14.021µs; +17.491µs] or [+5.182%; +6.464%]

scenario:PDOBench/benchPDOOverheadWithDBM-opcache

• 🟥 execution_time [+16.877µs; +19.368µs] or [+5.506%; +6.319%]

scenario:WordPressBench/benchWordPressOverhead

• 🟩 execution_time [-21.516ms; -21.399ms] or [-83.492%; -83.042%]