Restructured the VM/Vs folder layout while it's still feasible

src/Artemis.UI/Services/Dialog/DialogService.cs

@@ -1,4 +1,5 @@
 using System.Threading.Tasks;
+using Artemis.UI.Screens.Dialogs;
 using Artemis.UI.Services.Interfaces;
 using Artemis.UI.ViewModels.Dialogs;
 using MaterialDesignThemes.Wpf;

src/Artemis.UI/Services/Dialog/DialogViewModelBase.cs

@@ -0,0 +1,29 @@
+using Artemis.UI.ViewModels.Utilities;
+using MaterialDesignThemes.Wpf;
+using Stylet;
+
+namespace Artemis.UI.ViewModels.Dialogs
+{
+    public abstract class DialogViewModelBase : ValidatingModelBase
+    {
+        protected DialogViewModelBase(IModelValidator validator) : base(validator)
+        {
+        }
+
+        protected DialogViewModelBase()
+        {
+        }
+
+        public DialogViewModelHost DialogViewModelHost { get; set; }
+        public DialogSession Session { get; private set; }
+
+        public void OnDialogOpened(object sender, DialogOpenedEventArgs e)
+        {
+            Session = e.Session;
+        }
+
+        public virtual void OnDialogClosed(object sender, DialogClosingEventArgs e)
+        {
+        }
+    }
+}

src/Artemis.UI/Services/Dialog/DialogViewModelHost.cs

@@ -0,0 +1,29 @@
+using Artemis.UI.ViewModels.Dialogs;
+using MaterialDesignThemes.Wpf;
+using Stylet;
+
+namespace Artemis.UI.ViewModels.Utilities
+{
+    public class DialogViewModelHost : PropertyChangedBase
+    {
+        private readonly IViewManager _viewManager;
+
+        public DialogViewModelHost(IViewManager viewManager)
+        {
+            _viewManager = viewManager;
+        }
+
+        public DialogViewModelBase ActiveDialogViewModel { get; set; }
+        public bool IsOpen { get; set; }
+
+        public void OpenDialog(DialogViewModelBase viewModel, string dialogIdentifier)
+        {
+            var view = _viewManager.CreateViewForModel(viewModel);
+            DialogHost.Show(view, dialogIdentifier, viewModel.OnDialogClosed);
+            viewModel.DialogViewModelHost = this;
+
+            ActiveDialogViewModel = viewModel;
+            IsOpen = true;
+        }
+    }
+}