[RUM-16384] feat: add nativeIosResourceTrackingDisallowList RUM option

[marco-saia-datadog]

What does this PR do?

Introduces a RUM initialization option to exclude URLs from native iOS resource tracking:

rumConfiguration: {
    nativeIosResourceTrackingDisallowList?: string[]
}

The list is passed to the iOS SDK's URLSessionTracking(disallowList:). Patterns are matched against the full URL: plain strings match exactly, and * matches any characters. Matching requests are not tracked as RUM resources, and they get no trace headers and no APM span.

Builds on #1459.

Motivation

Native iOS resource tracking can now be turned on or off (#1459), but there is still no way to filter what it tracks. The native resource event mapper is internal to the RN SDK, so customers cannot drop unwanted native resources, such as third-party SDK traffic. A mapper also couldn't stop trace header injection, which the disallow list does.

Changes

• JS: the option is added to RumConfiguration, DatadogProviderConfiguration, the async/partial init configs, FileBasedConfiguration and datadog-configuration.schema.json. Patterns are not validated in JS; the iOS SDK drops invalid ones (e.g. "*") with a warning.
• iOS: both parsers (JS bridge and native-init JSON) read the option and default to []. buildRumConfiguration passes it to URLSessionTracking only when native tracking is enabled. If the list is set while tracking is disabled, it is ignored and a DD.logger warning is printed (subject to verbosity).
• Android: no changes. The option has no effect on Android, where the native SDK has no automatic HTTP instrumentation.
• Tests: Jest covers how the option flows through every config path. The new XCTests cover both parsers, the list being applied when tracking is on, being ignored with a warning when tracking is off, and the [] default.

Compatibility

Existing apps see no behavior change unless they explicitly set the new option.

Testing

• Jest: 847 passed, 1 skipped
• iOS XCTests (DatadogSDKReactNative test scheme)

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests
• Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING (CONTRIBUTING.md) doc)
• If this PR is auto-generated, please make sure also to manually update the code related to the change

[datadog-official]

✅ All CI checks and tests passed.

🎉 All green!

🧪 All tests passed
❄️ No new flaky tests detected

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