Populate trace_ids in mobile replay events to enable searching replays by trace ID

## Problem

When searching for replays by trace ID in Sentry's Explore UI, mobile replays from React Native are not discoverable. While web replay (via JS SDK) collects `trace_ids`, the mobile replay integration does not.

## Solution

The `mobileReplayIntegration` should collect trace IDs when transactions are captured and pass them to the native replay system.

### Reference implementations
- JS (web replay): https://github.com/getsentry/sentry-javascript/blob/30eb68fff5077211c30c61ba74625e66ab514870/packages/replay-internal/src/coreHandlers/handleAfterSendEvent.ts#L34-L43
- Java (Android native): https://github.com/getsentry/sentry-java/pull/5473

### Key points
- Collect trace IDs when transactions are successfully captured during replay recording
- Limit to max 100 trace IDs per segment (matching JS SDK)
- Need a bridge mechanism to pass trace IDs from JS transactions to native replay
- Android native SDK (sentry-java) now supports `registerTraceId()` — need similar support in iOS (sentry-cocoa)

### Dependencies
- sentry-cocoa needs to implement `trace_ids` support first (or in parallel)

Action taken on behalf of Roman Zavarnitsyn.