Bump to Swift 5.7 and Xcode 14

Examples/Package.swift

-// swift-tools-version:5.6
+// swift-tools-version:5.7
 // This file makes Xcode doesn't display this directory inside swift package.
 import PackageDescription
 let package = Package(name: "", products: [], targets: [])

Examples/xx-messenger/Package.swift

-// swift-tools-version: 5.6
+// swift-tools-version: 5.7
 import PackageDescription
 
 let swiftSettings: [SwiftSetting] = [

Package.swift

-// swift-tools-version: 5.6
-
+// swift-tools-version: 5.7
 import PackageDescription
 
 let swiftSettings: [SwiftSetting] = [

README.md

 # Elixxir dApps Swift SDK
 
-![Swift 5.6](https://img.shields.io/badge/swift-5.6-orange.svg)
+![Swift 5.7](https://img.shields.io/badge/swift-5.7-orange.svg)
 ![platform iOS, macOS](https://img.shields.io/badge/platform-iOS,_macOS-blue.svg)
 
 ## 📖 Documentation 
@@ -14,7 +14,7 @@ Check out included [examples](Examples).
 
 ## 🛠 Development
 
-Open `Package.swift` in Xcode (≥13.4.1).
+Open `Package.swift` in Xcode (≥14).
 
 ### Project structure