appsec: new user monitoring SDK telemetry

[RomainMuller]

Adds the new user monitoring SDK telemetry as specified by RFC-1017. This is used to track usage of the old & new APIs for user monitoring.

Reviewer's Checklist

• Changed code has unit tests for its functionality at or near 100% coverage.
• System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
• There is a benchmark for any new code, or changes to existing code.
• If this interacts with the agent in a new way, a system test has been added.
• Add an appropriate team label so this PR gets put in the right place for the release notes.
• Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild.
• For internal contributors, a matching PR should be created to the v2-dev branch and reviewed by @DataDog/apm-go.

Unsure? Have a question? Request a review!

[datadog-datadog-prod-us1]

Datadog Report

Branch report: romain.marcadier/APPSEC-56555/ato-sdk-consolidation
Commit report: 4825aa8
Test service: dd-trace-go

❌ 1 Failed (1 Known Flaky), 4385 Passed, 64 Skipped, 3m 45.68s Total Time

❌ Failed Tests (1)

• TestAnalyticsSettings - github.com/DataDog/dd-trace-go/contrib/gorm.io/gorm.v1/v2 - ❄️ Known flaky - Details

  Expand for error

   
   2025/03/19 11:44:34 �[31;1m/home/runner/work/dd-trace-go/dd-trace-go/contrib/gorm.io/gorm.v1/gorm_test.go:419 �[35;1minsufficient arguments
   �[0m�[33m[0.310ms] �[34;1m[rows:-]�[0m SELECT * FROM "products" LIMIT 1
   2025/03/19 11:44:34 insufficient arguments
  

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-03-19 12:09:17

Comparing candidate commit 8a4c2ce in PR branch romain.marcadier/APPSEC-56555/ato-sdk-consolidation with baseline commit 75ae7cd in branch v2-dev.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 56 metrics, 0 unstable metrics.