Created middleware to drop domain from query when it is the default one

module/Rest/src/Middleware/ShortUrl/DropDefaultDomainFromQueryMiddleware.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Rest\Middleware\ShortUrl;
+
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\MiddlewareInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+
+class DropDefaultDomainFromQueryMiddleware implements MiddlewareInterface
+{
+    private string $defaultDomain;
+
+    public function __construct(string $defaultDomain)
+    {
+        $this->defaultDomain = $defaultDomain;
+    }
+
+    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
+    {
+        $query = $request->getQueryParams();
+        if (isset($query['domain']) && $query['domain'] === $this->defaultDomain) {
+            unset($query['domain']);
+            $request = $request->withQueryParams($query);
+        }
+
+        return $handler->handle($request);
+    }
+}