[8.x] Add has() method to ComponentAttributeBag (#35562)

* Add has() method to ComponentAttributeBag

* Update ComponentAttributeBag.php

Co-authored-by: Taylor Otwell <taylor@laravel.com>

src/Illuminate/View/ComponentAttributeBag.php

@@ -56,6 +56,17 @@ public function get($key, $default = null)
         return $this->attributes[$key] ?? value($default);
     }
 
+    /**
+     * Determine if a given attribute exists in the attribute array.
+     *
+     * @param  string  $key
+     * @return bool
+     */
+    public function has($key)
+    {
+        return array_key_exists($key, $this->attributes);
+    }
+
     /**
      * Only include the given attribute from the attribute array.
      *