Swift Package Manager Support

[lishaduck]

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

Not really.

Describe the solution you'd like

Add in swiftpm support.

Describe alternatives you've considered

Wait for swiftpm to be the default.

Additional context

Flutter is switching to use the Swift Package Manager instead of Cocoapods. Each plugin a package depends on needs to be updated before a project can upgrade.

Also, I'm on macOS. I haven't written Swift in ages, but I'd be willing to give this a shot!

[ThexXTURBOXx]

Feel free to propose a PR. However, I probably won't merge it until it is stable and the default.
As long as Cocoapods is the default and one needs to explicitly enable the new system, there is really no point in migrating