How to get running window informations in macOS

Issue #243

From https://developer.apple.com/documentation/coregraphics/1455137-cgwindowlistcopywindowinfo

Generates and returns information about the selected windows in the current user session.

struct MyWindowInfo {
    let frame: CGRect
    let name: String
    let pid: Int
    let number: Int

    init?(json: [String: Any]) {
        guard let pid = json["kCGWindowOwnerPID"] as? Int else {
            return nil
        }

        guard let name = json["kCGWindowOwnerName"] as? String else {
            return nil
        }

        guard let rect = json["kCGWindowBounds"] as? [String: Any] else {
            return nil
        }

        guard let x = rect["X"] as? CGFloat else {
            return nil
        }

        guard let y = rect["Y"] as? CGFloat else {
            return nil
        }

        guard let height = rect["Height"] as? CGFloat else {
            return nil
        }

        guard let width = rect["Width"] as? CGFloat else {
            return nil
        }

        guard let number = json["kCGWindowNumber"] as? Int else {
            return nil
        }

        self.pid = pid
        self.name = name
        self.number = number
        self.frame = CGRect(x: x, y: y, width: width, height: height)
    }
}

guard let jsons = CGWindowListCopyWindowInfo(.optionAll, kCGNullWindowID) as? [[String: Any]] else {
    return
}

let infos = jsons.compactMap({ MyWindowInfo(json: $0) })