Minor Performance Optimization by Reducing Calls to AppDomain.CurrentDomain.FriendlyName (#8567)

* Minor Optimize Performance by Reducing Calls to `AppDomain.CurrentDomain.FriendlyName`

I have optimized the performance by reducing the number of times `AppDomain.CurrentDomain.FriendlyName` property is accessed. Accessing the FriendlyName property is not cheap and results in some additional performance overhead. By assigning it to a local variable first, I have managed to reduce multiple property accesses, thereby slightly improving performance without altering the existing logic.

```
    public sealed partial class AppDomain : MarshalByRefObject
    {
        public string FriendlyName
        {
            get
            {
                Assembly? assembly = Assembly.GetEntryAssembly();
                return assembly != null ? assembly.GetName().Name! : "DefaultDomain";
            }
        }
   }
```

* Using the special string type

Author: lindexi

src/Microsoft.DotNet.Wpf/src/Shared/MS/Win32/HwndWrapper.cs

@@ -95,10 +95,11 @@ public HwndWrapper(
             // Register will fail if the string gets over 255 in length.
             // So limit each part to a reasonable amount.
             string appName;
-            if(null != AppDomain.CurrentDomain.FriendlyName && 128 <= AppDomain.CurrentDomain.FriendlyName.Length)
-                appName = AppDomain.CurrentDomain.FriendlyName.Substring(0, 128);
+            string currentDomainFriendlyName = AppDomain.CurrentDomain.FriendlyName;
+            if (null != currentDomainFriendlyName && 128 <= currentDomainFriendlyName.Length)
+                appName = currentDomainFriendlyName[..128];
             else
-                appName = AppDomain.CurrentDomain.FriendlyName;
+                appName = currentDomainFriendlyName;
 
             string threadName;
             if(null != Thread.CurrentThread.Name && 64 <= Thread.CurrentThread.Name.Length)