[Messenger example] create new group

xx-messenger example

• Add groups list screen
• Add new group screen
• Implement creating new group

Examples/xx-messenger/Sources/AppCore/SharedUI/GroupAuthStatusView.swift

+import SwiftUI
+import XXModels
+
+public struct GroupAuthStatusView: View {
+  public init(_ authStatus: XXModels.Group.AuthStatus) {
+    self.authStatus = authStatus
+  }
+
+  public var authStatus: XXModels.Group.AuthStatus
+
+  public var body: some View {
+    switch authStatus {
+    case .pending:
+      HStack {
+        Text("Pending")
+        Spacer()
+        Image(systemName: "envelope.badge")
+      }
+
+    case .deleting:
+      HStack {
+        Text("Deleting")
+        Spacer()
+        ProgressView()
+      }
+
+    case .participating:
+      HStack {
+        Text("Participating")
+        Spacer()
+        Image(systemName: "checkmark")
+      }
+
+    case .hidden:
+      HStack {
+        Text("Hidden")
+        Spacer()
+        Image(systemName: "eye.slash")
+      }
+    }
+  }
+}
+
+#if DEBUG
+struct GroupAuthStatusView_Previews: PreviewProvider {
+  static var previews: some View {
+    NavigationView {
+      Form {
+        Section { GroupAuthStatusView(.pending) }
+        Section { GroupAuthStatusView(.deleting) }
+        Section { GroupAuthStatusView(.participating) }
+        Section { GroupAuthStatusView(.hidden) }
+      }
+    }
+  }
+}
+#endif