misc: Move StatusBarSeparator into Controls namespace, rename to MiniVerticalSeparator

add bulk property change event method
give each markup extension its own property name

src/Ryujinx/UI/ViewModels/BaseModel.cs

@@ -1,3 +1,4 @@
+using System;
 using System.ComponentModel;
 using System.Runtime.CompilerServices;
 
@@ -11,5 +12,13 @@ namespace Ryujinx.Ava.UI.ViewModels
         {
             PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
         }
+        
+        protected void OnPropertiesChanged(params ReadOnlySpan<string> propertyNames)
+        {
+            foreach (var propertyName in propertyNames)
+            {
+                OnPropertyChanged(propertyName);
+            }
+        }
     }
 }