Add overload to find calls in a chat response by tool name

Author: kzu

src/AI/ToolExtensions.cs

@@ -26,6 +26,12 @@ public static class ToolExtensions
     public static IEnumerable<ToolCall> FindCalls(this ChatResponse response, AIFunction tool)
         => FindCalls(response.Messages, tool.Name);
 
+    /// <summary>
+    /// Looks for calls to a tool and their outcome.
+    /// </summary>
+    public static IEnumerable<ToolCall> FindCalls(this ChatResponse response, string tool)
+        => FindCalls(response.Messages, tool);
+
     /// <summary>
     /// Looks for calls to a tool and their outcome.
     /// </summary>