This commit adds the  method to the C++
Analytics API. This method allows setting default event parameters,
mirroring functionality in the iOS and Android SDKs.

The implementation covers:
- iOS: Using Objective-C++ to call the
- Android: Using JNI to call the
- Desktop: A stub implementation for other platforms.

Unit tests and integration tests were added to ensure the change works
as intended.

A release note was added for the next release (v12.7.0) in
- Analytics: Added support for default parameters to be sent with each event.
  This change lets you use  to set default
  parameters to be sent with each event.
- General (iOS): Update to Firebase Cocoapods version 11.9.0.
- General (Android): Update to Firebase Android BoM version 33.10.0.

All the references to  in the test files were corrected to have the  namespace added.