Add addUserExtraInfo method to ObjC API

[0xnm]

What and why?

This method was missing in ObjC API, despite being present in Swift.

Review checklist

• Feature or bugfix MUST have appropriate tests (unit, integration)
• Make sure each commit and the PR mention the Issue number or JIRA reference
• Add CHANGELOG entry for user facing changes

Custom CI job configuration (optional)

• Run unit tests for Core, RUM, Trace, Logs, CR and WVT
• Run unit tests for Session Replay
• Run integration tests
• Run smoke tests
• Run tests for tools/

[datadog-datadog-prod-us1]

Datadog Report

Branch report: nogorodnikov/add-addExtraUserInfo-to-objc
Commit report: 30d8fdc
Test service: dd-sdk-ios

✅ 0 Failed, 2763 Passed, 0 Skipped, 5m 57.41s Wall Time
🔻 Test Sessions change in coverage: 8 decreased, 5 increased

🔻 Code Coverage Decreases vs Default Branch (8)

This report shows up to 5 code coverage decreases.

• test DatadogLogsTests tvOS 45.1% (-0.27%) - Details
• test DatadogLogsTests iOS 45.05% (-0.27%) - Details
• test DatadogCoreTests tvOS 79.37% (-0.26%) - Details
• test DatadogCrashReportingTests iOS 27.71% (-0.18%) - Details
• test DatadogCrashReportingTests tvOS 27.74% (-0.16%) - Details

[maxep]

Thanks 👍