feat: Add support to Swift Package Manager

[fbernaly]

No description provided.

[fbernaly]

@bensonarafat : could you review?

[bensonarafat]

Okay

[bensonarafat]

Is the dir not wrong? @fbernaly
Just going through the reference here https://docs.flutter.dev/packages-and-plugins/swift-package-manager/for-plugin-authors

it says, create a folder with the plugin name in the iOS folder
that is packages/plugin_name/ios/plugin_name/Package.swift

[fbernaly]

Google's ML Kit is not officially available with Swift Package Manager (SPM) for iOS. The official and supported method for integrating ML Kit into an iOS project is currently through CocoaPods.
ML Kit's libraries are provided as CocoaPods, and there is no official first-party support for SPM at this time.

Related:

• https://stackoverflow.com/questions/77363135/integrating-google-ml-kit-for-ios-without-using-pod-cocoapod
• https://github.com/d-date/google-mlkit-swiftpm
• https://developers.google.com/ml-kit/migration/ios

For now these Flutter plugin will stick with the official supported libraries that is Cocoapods.