Moved query string builder and marked as internal

Author: GrahamCampbell

lib/Gitlab/Api/AbstractApi.php

@@ -4,8 +4,8 @@
 
 use Gitlab\Client;
 use Gitlab\Exception\RuntimeException;
-use Gitlab\HttpClient\Message\QueryStringBuilder;
 use Gitlab\HttpClient\Message\ResponseMediator;
+use Gitlab\HttpClient\Util\QueryStringBuilder;
 use Http\Discovery\StreamFactoryDiscovery;
 use Http\Message\MultipartStream\MultipartStreamBuilder;
 use Http\Message\StreamFactory;

lib/Gitlab/HttpClient/Message/QueryStringBuilder.php renamed to lib/Gitlab/HttpClient/Util/QueryStringBuilder.php

@@ -1,7 +1,10 @@
 <?php
 
-namespace Gitlab\HttpClient\Message;
+namespace Gitlab\HttpClient\Util;
 
+/**
+ * @internal
+ */
 final class QueryStringBuilder
 {
     /**