Fix complication issues on Xcode 16

[maciejburda]

What and why?

Resolve compilation issue reported in #1892

Issue is that in new version of Xcode, the copied signature function:
open func beginBackgroundTask(expirationHandler handler: (() -> Void)? = nil) -> UIBackgroundTaskIdentifier is enriched with @MainActor resulting in a conflict.

This PR renames those functions signatures and adds extension that calls corresponding UIApplication functions.

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: maciey/fix-xcode16-compliation-issues
Commit report: 3358707
Test service: dd-sdk-ios

✅ 0 Failed, 3058 Passed, 0 Skipped, 2m 21.84s Total Time
🔻 Test Sessions change in coverage: 7 decreased, 6 increased

🔻 Code Coverage Decreases vs Default Branch (7)

This report shows up to 5 code coverage decreases.

• test DatadogTraceTests tvOS 54.85% (-0.28%) - Details
• test DatadogCrashReportingTests tvOS 27.21% (-0.12%) - Details
• test DatadogCrashReportingTests iOS 27.17% (-0.1%) - Details
• test DatadogLogsTests tvOS 46.03% (-0.07%) - Details
• test DatadogLogsTests iOS 45.97% (-0.06%) - Details

[maciejburda]

Related to #1896 and #1895

I think it's better to change the protocol and be more explicit.

[maxep]

👍