Implemented ThrowObjectDisposedException for the ThrowHelper, replaced raw throws with this in Image/ImageFrameCollection

src/ImageSharp/Image.cs

@@ -161,7 +161,7 @@ namespace SixLabors.ImageSharp
         {
             if (this.isDisposed)
             {
-                throw new ObjectDisposedException("Trying to execute an operation on a disposed image.");
+                ThrowHelper.ThrowObjectDisposedException(this.GetType());
             }
         }
 

src/ImageSharp/ImageFrameCollection.cs

@@ -196,9 +196,9 @@ namespace SixLabors.ImageSharp
         /// </summary>
         protected void EnsureNotDisposed()
         {
-            if(this.isDisposed)
+            if (this.isDisposed)
             {
-                throw new ObjectDisposedException("Trying to execute an operation on a disposed image frame.");
+                ThrowHelper.ThrowObjectDisposedException(this.GetType());
             }
         }