Adopt Schema component in server handlers

tests/Fixtures/InMemoryTransport.php

@@ -1,50 +0,0 @@
-<?php
-
-/*
- * This file is part of the official PHP MCP SDK.
- *
- * A collaboration between Symfony and the PHP Foundation.
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Mcp\Tests\Fixtures;
-
-use Mcp\Server\TransportInterface;
-
-class InMemoryTransport implements TransportInterface
-{
-    private bool $connected = true;
-
-    /**
-     * @param list<string> $messages
-     */
-    public function __construct(
-        private readonly array $messages = [],
-    ) {
-    }
-
-    public function initialize(): void
-    {
-    }
-
-    public function isConnected(): bool
-    {
-        return $this->connected;
-    }
-
-    public function receive(): \Generator
-    {
-        yield from $this->messages;
-        $this->connected = false;
-    }
-
-    public function send(string $data): void
-    {
-    }
-
-    public function close(): void
-    {
-    }
-}