fix(sdk): Set {{auto}} if user.ip_address is undefined

[krystofwoldrich]

📢 Type of change

• Bugfix
• Enhancement

❓ What to do for RN v6?

Map current behaviour for RN JS, Cocoa, Android and Android Native.

Plat	Relay adds	SDK adds
RN JS
Cocoa
Android
Android Native

🛑 Blocked by JS v9

• feat(browser): Set user.ip_address explicitly to {{auto}} sentry-javascript#15008 (mandatory to use the client hooks)
• chore(browser): Export ipAddress helpers for use in other SDKs sentry-javascript#15079 (optional to avoid code duplication)

💡 Motivation and Context

• meta issue Explicity set user.ip_address: {{auto}} team-sdks#118
• fixes: Explicity set user.ip_address: {{auto}} #4462

💚 How did you test it?

unit tests

📝 Checklist

• I added tests to verify 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.
• All tests passing
• No breaking changes