New Database settings page

Implements Recycle Bin (new group creation still needs to be implemented)
Code refactoring

ModernKeePass/Interfaces/IPwEntity.cs

@@ -11,9 +11,21 @@ namespace ModernKeePass.Interfaces
         string Name { get; set; }
         bool IsEditMode { get; }
 
+        /// <summary>
+        /// Delete from Model
+        /// </summary>
         void CommitDelete();
+        /// <summary>
+        /// Restore ViewModel
+        /// </summary>
         void UndoDelete();
+        /// <summary>
+        /// Save changes to Model
+        /// </summary>
         void Save();
+        /// <summary>
+        /// Delete from ViewModel
+        /// </summary>
         void MarkForDelete();
     }
 }