Move login and registration to login

To make this work `AccountManager` is split off from controller taking all the code around `AccountRegister` and is added to LibNeoChat as it makes sense to have this functionality there.

src/qml/Main.qml

@@ -64,6 +64,13 @@ Kirigami.ApplicationWindow {
         }
     }
 
+    Connections {
+        target: Registration
+        function onLoaded() {
+            root.load();
+        }
+    }
+
     Connections {
         target: root.quitAction
         function onTriggered() {