refactor: extract test user data and improve "New offers" test flow

- Extract test user data (seed phrases, DIDs, usernames) from importUser into separate getTestUserData function
- Refactor importUser to use getTestUserData internally, maintaining backward compatibility
- Update "New offers for another user" test to use new getTestUserData function
- Replace hardcoded seed phrase with programmatic retrieval using getTestUserData('00')
- Add proper TypeScript type annotations to array functions in testUtils
- Improve test maintainability by centralizing test user data management

This allows tests to access user data without executing import flow, providing more flexibility for test scenarios.

src/utils/PlatformServiceMixin.ts

@@ -707,6 +707,7 @@ export const PlatformServiceMixin = {
         // Merge with any provided defaults (these take highest precedence)
         const finalSettings = { ...mergedSettings, ...defaults };
 
+        console.log("[PlatformServiceMixin] $accountSettings", JSON.stringify(finalSettings, null, 2));
         return finalSettings;
       } catch (error) {
         logger.error(