title: SwiftUI: List in a Tabview always reset after tab change
body: <p>In my app I have a TabView with lists in there.
  When I scroll a list and than change tabs forth and back, the list is always reset and starts from the top...</p>
  
  <p>But this shouldn't be the case...
  Is this a bug, or what I'm doing wrong?</p>
  
  <p>Here is some example code:</p>
  
  <pre><code>struct ContentView: View {
     var body: some View {
         TabView {
              NavigationView {
                  List {
                      ForEach((1...50), id: \.self) {
                          Text("Row in Tab 1 Number: \($0)")
                      }
                  }
                  .navigationBarTitle("Tab 1")
              }.tabItem {
                  Image(systemName: "bubble.right")
                  Text("Tab 1")
              }.tag(0)
  
              NavigationView {
                  List {
                      ForEach((1...50), id: \.self) {
                          Text("Row in Tab 2 Number: \($0)")
                      }
                  }
                  .navigationBarTitle("Tab 2")
              }.tabItem {
                  Image(systemName: "bubble.left")
                  Text("Tab 2")
              }.tag(1)
          }.edgesIgnoringSafeArea(.top)
      }
  }
  </code></pre>