Fix memory leak in Compose masking for Session Replay

[romtsn]

📜 Description

Use WeakReference to store root coordinates and add a test for leaks in replay

💡 Motivation and Context

Closes #3915

💚 How did you test it?

Manually + automated

📝 Checklist

• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

🔮 Next steps

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	407.10 ms	443.43 ms	36.33 ms
Size	1.70 MiB	2.36 MiB	672.25 KiB