API: Split BuildClientView into two separate events

Much easier to work with. Extension stub hasn't been updated yet.

src/Events/BuildAdminClientView.php

@@ -0,0 +1,34 @@
+<?php
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Flarum\Events;
+
+use Flarum\Support\ClientView;
+use Flarum\Admin\Actions\ClientAction;
+
+class BuildAdminClientView extends BuildClientView
+{
+    /**
+     * @var ClientAction
+     */
+    public $action;
+
+    /**
+     * @param ClientAction $action
+     * @param ClientView $view
+     * @param array $keys
+     */
+    public function __construct(ClientAction $action, ClientView $view, array &$keys)
+    {
+        $this->action = $action;
+        $this->view = $view;
+        $this->keys = &$keys;
+    }
+}