Add a super basic implementation of Combine and SwiftUI sample project

[JonMercer]

• adds a combine wrapper to SAPlayer.Update
• use the wrapper in a SwiftUI friendly way

[JonMercer]

T, could you try running the project on your end? I didn't actually use the podfile, but instead linked (symlink I guess?) to the source files directly. My guess was that some users might just want an example to use in their project.

I ran the UIKit project and I had a bunch of podfiles and plist stuff leftover that I didn't think I should commit.

[jiangdi0924]

• adds a combine wrapper to SAPlayer.Update
• use the wrapper in a SwiftUI friendly way

it's great !