Add FTUE display name screen.

Use UserSession instead of userId & MXSession in OnboardingCoordinator

RiotSwiftUI/Modules/Onboarding/DisplayName/OnboardingDisplayNameModels.swift

@@ -0,0 +1,40 @@
+// 
+// Copyright 2021 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Foundation
+
+// MARK: View model
+
+enum OnboardingDisplayNameViewModelResult {
+    // Can probably be removed
+}
+
+// MARK: View
+
+struct OnboardingDisplayNameViewState: BindableState {
+    var isWaiting = false
+    var bindings: OnboardingDisplayNameBindings
+}
+
+struct OnboardingDisplayNameBindings {
+    var displayName: String
+    var alertInfo: AlertInfo<Int>?
+}
+
+enum OnboardingDisplayNameViewAction {
+    case save
+    case skip
+}