SSE ClientTransport fixes and tests (#27)

SSE fixes
Additional SSE integration tests with everything server

tests/mcpdotnet.Tests/EverythingSseServerFixture.cs

@@ -0,0 +1,63 @@
+using System.Diagnostics;
+
+namespace McpDotNet.Tests;
+
+public class EverythingSseServerFixture : IAsyncDisposable
+{
+    private Process _process;
+
+    public async Task StartAsync()
+    {
+        var processStartInfo = new ProcessStartInfo
+        {
+            FileName = "docker",
+            Arguments = "run -p 3001:3001 --rm tzolov/mcp-everything-server:v1",
+            RedirectStandardInput = true,
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            UseShellExecute = false,
+        };
+
+        _process = Process.Start(processStartInfo);
+
+        // Wait for the server to start
+        await Task.Delay(10000);
+    }
+    public async ValueTask DisposeAsync()
+    {
+        try
+        {
+            // Find the container ID
+            var psInfo = new ProcessStartInfo
+            {
+                FileName = "docker",
+                Arguments = "ps -q --filter ancestor=tzolov/mcp-everything-server:v1",
+                RedirectStandardOutput = true,
+                UseShellExecute = false
+            };
+
+            using var psProcess = Process.Start(psInfo);
+            string containerId = await psProcess.StandardOutput.ReadToEndAsync();
+            containerId = containerId.Trim();
+
+            if (!string.IsNullOrEmpty(containerId))
+            {
+                // Stop the container
+                var stopInfo = new ProcessStartInfo
+                {
+                    FileName = "docker",
+                    Arguments = $"stop {containerId}",
+                    UseShellExecute = false
+                };
+
+                using var stopProcess = Process.Start(stopInfo);
+                await stopProcess.WaitForExitAsync();
+            }
+        }
+        catch (Exception ex)
+        {
+            // Log the exception but don't throw
+            Console.Error.WriteLine($"Error stopping Docker container: {ex.Message}");
+        }
+    }
+}