feat: Expose `attachAllThreads` option from Cocoa SDK

[antonis]

Summary

The Cocoa SDK v9.9.0 added a new attachAllThreads option to SentryOptions that attaches full stack traces for all threads to captured events. It also supports per-call overrides via capture(event:), capture(error:), capture(exception:), and capture(message:).

• Cocoa SDK #7764 — attachAllThreads option
• Cocoa SDK #7767 — Per-call attachAllThreads parameter

Motivation

This option is currently only available to native Cocoa SDK users. React Native users should be able to configure attachAllThreads from JS via Sentry.init() options so it gets forwarded to the native iOS SDK.

Acceptance Criteria

• Add attachAllThreads to ReactNativeOptions
• Forward the option to the native iOS SDK during initialization
• Document the new option

[linear-code]

RN-571