Client management

• Download NDF.
• Generate a secure password.
• Handle secure password storage with the iOS keychain.
• Create and store a new client.
• Load stored client.
• Remove stored client.
• Example app with all of the above.

Example/ExampleApp/Sources/ErrorFeature/ErrorFeature.swift

@@ -2,7 +2,11 @@ import ComposableArchitecture
 import SwiftUI
 
 public struct ErrorState: Equatable {
-  public init() {}
+  public init(error: NSError) {
+    self.error = error
+  }
+
+  var error: NSError
 }
 
 public enum ErrorAction: Equatable {}