Add Swift Package Manager support

[loic-sharma]

Is your feature request related to a problem? Please describe.
Hello,

Flutter is migrating to Swift Package Manager. Please add Swift Package Manager support to your plugin.

Flutter will eventually deprecate and then remove support for CocoaPods. Adding Swift Package Manager support future-proofs your plugins.

How to add Swift Package Manager support to your plugins

You can find the migration guide here: https://docs.flutter.dev/packages-and-plugins/swift-package-manager/for-plugin-authors#how-to-add-swift-package-manager-support-to-an-existing-flutter-plugin

If you run into issues or have questions, please reach out to the Flutter team. You can ping me at @loic-sharma, send a message to the #hackers-ios channel on Flutter’s discord, or open a GitHub issue.

Thank you for your wonderful contributions to the Flutter ecosystem!

Why is Flutter migrating to Swift Package Manager?

CocoaPods is now in maintenance mode.

Swift Package Manager support is one of Flutter’s most requested features: flutter#33850.

Flutter's Swift Package Manager integration has several benefits:

1. Access to the Swift package ecosystem. Flutter plugins can use the growing ecosystem of Swift packages.
2. Simplifies Flutter installation. Swift Package Manager is bundled with Xcode. In the future, you won’t need to install Ruby and CocoaPods to target iOS or macOS.

Describe the solution you'd like
Add Swift Package Manager support

Describe alternatives you've considered
N/A

Additional context
N/A