Add EverythingServer sample (#151)

samples/EverythingServer/Tools/LongRunningTool.cs

@@ -0,0 +1,39 @@
+using ModelContextProtocol;
+using ModelContextProtocol.Protocol.Messages;
+using ModelContextProtocol.Protocol.Types;
+using ModelContextProtocol.Server;
+using System.ComponentModel;
+
+namespace EverythingServer.Tools;
+
+[McpServerToolType]
+public class LongRunningTool
+{
+    [McpServerTool(Name = "longRunningOperation"), Description("Demonstrates a long running operation with progress updates")]
+    public static async Task<string> LongRunningOperation(
+        IMcpServer server,
+        RequestContext<CallToolRequestParams> context,
+        int duration = 10,
+        int steps = 5)
+    {
+        var progressToken = context.Params?.Meta?.ProgressToken;
+        var stepDuration = duration / steps;
+
+        for (int i = 1; i <= steps + 1; i++)
+        {
+            await Task.Delay(stepDuration * 1000);
+            
+            if (progressToken is not null)
+            {
+                await server.SendNotificationAsync("notifications/progress", new
+                    {
+                        Progress = i,
+                        Total = steps,
+                        progressToken
+                    });
+            }
+        }
+
+        return $"Long running operation completed. Duration: {duration} seconds. Steps: {steps}.";
+    }
+}