Remove confirm template obsolete uses (except for contacts)

- Remove obsolete explode_querystring() function
- Remove $extra_inputs template variable

src/Core/Addon.php

@@ -229,8 +229,6 @@ class Addon
 	 */
 	public static function getInfo($addon)
 	{
-		$a = DI::app();
-
 		$addon = Strings::sanitizeFilePathItem($addon);
 
 		$info = [