feat(device_info_plus): Add Swift Package Manager support

[charafau]

ref: https://github.com/fluttercommunity/plus_plugins/issues/3152

Since SPM support is comming I plan to add it to all plugins.

Followed the guide - https://docs.flutter.dev/packages-and-plugins/swift-package-manager/for-plugin-authors and checked it for both cocoapods and spm

[charafau]

I am not super familiar with the process yet, but took a look at it, and left some comments.

Also, we should do the same for the macOS part of the project, right? In that case, we should indicate in the Title that this only covers iOS

Thanks for fast review, this is also my first time doing it. I will apply suggestions from you and @koji-1009 and upload today. Hopefully migrate all plugins

[charafau]

Thanks guys, should be good now. I also added support for macos

[miquelbeltran]

Please take a look at the macos CI jobs, as they are now failing.

[charafau]

Please take a look at the macos CI jobs, as they are now failing.

Sorry didn't notice that it's a scrollable list 😅 fixed and is passing now