Improved debugging experience

Author: sakno

src/DotNext.IO/Runtime/Caching/DiskSpacePool.FreeList.cs

@@ -81,5 +81,7 @@ internal bool TryGetNext(out SegmentHandle? next)
         internal void MoveToDisposedState() => ownerOrNext = Sentinel.Instance;
 
         internal long Offset => offset;
+
+        public override string ToString() => offset.ToString();
     }
 }

src/DotNext.IO/Runtime/Caching/DiskSpacePool.cs

@@ -314,7 +314,7 @@ private static async ValueTask ReleaseSegmentAsync(SegmentHandle handle)
         }
 
         /// <inheritdoc/>
-        public override string? ToString() => handle?.Offset.ToString();
+        public override string? ToString() => handle?.ToString();
     }
 
     /// <summary>