revert: Moved message stack trace back to exception (fixes symbolication)

[lucas-zimerman]

📢 Type of change

• Bugfix
• New feature
• Enhancement
• Refactoring

📜 Description

This PR rollsback the behaviour of moving the stack-trace from the threads to the exception, allowing message stack-trace to be symbolicated.

Before the change:

After the change:
https://sentry-sdks.sentry.io/issues/5016987060/events/2ae9c7850dde44c4a5458f6820d71724/?project=5428561

Fixes #3097

💡 Motivation and Context

💚 How did you test it?

📝 Checklist

• I reviewed submitted code
• I added tests to verify changes
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled
• All tests passing
• No breaking changes

🔮 Next steps

[github-actions]

Android (legacy) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	393.89 ms	436.35 ms	42.46 ms
Size	17.73 MiB	19.93 MiB	2.19 MiB

[lucas-zimerman]

@krystofwoldrich I added a break-change because it generated a new issue group compared to not using this change.

Q: Should we keep the debugsymbolicator code for threads?

sentry-react-native/src/js/integrations/debugsymbolicator.ts

Lines 60 to 64 in f63f870

	} else if (event.threads) {
	// RN JS doesn't have threads
	// syntheticException is used for Sentry.captureMessage() threads
	symbolicatedFrames && this._replaceThreadFramesInEvent(event, symbolicatedFrames);
	}

[krystofwoldrich]

@lucas-zimerman Thank you, can you confirm #2131 still works after moving the stack back to expcetion, as that was the reason to move it to threads?

[krystofwoldrich]

@krystofwoldrich I added a break-change because it generated a new issue group compared to not using this change.

Q: Should we keep the debugsymbolicator code for threads?

sentry-react-native/src/js/integrations/debugsymbolicator.ts

Lines 60 to 64 in f63f870

	} else if (event.threads) {
	// RN JS doesn't have threads
	// syntheticException is used for Sentry.captureMessage() threads
	symbolicatedFrames && this._replaceThreadFramesInEvent(event, symbolicatedFrames);
	}

Yes, let's keep the symbolication for threads in, but let's remove the comment about thread being used in captureMessage.

[krystofwoldrich]

I agree with the breaking-change label, I'll create v6 branch and we can merge it there.

[lucas-zimerman]

@lucas-zimerman Thank you, can you confirm #2131 still works after moving the stack back to expcetion, as that was the reason to move it to threads?

will check and update this comment

[github-actions]

iOS (legacy) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1222.52 ms	1224.81 ms	2.29 ms
Size	2.36 MiB	2.92 MiB	569.85 KiB

[github-actions]

Android (new) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	370.29 ms	432.08 ms	61.80 ms
Size	7.15 MiB	8.20 MiB	1.05 MiB