Pass $dependencies to Cache::load() for saving fallback result

So instead of:
```php
$article = $cache->load($id);
if ($article === null) {
	$article = $db->getArticle($id);
	$cache->save($id, $article, [ Cache::TAGS => [ 'articles', "articles/$id" ] ]);
}
```
you can write just:
```php
$article = $cache->load($id, function() use ($db, $id) {
	return $db->getArticle($id);
}, [ Cache::TAGS => [ 'articles', "articles/$id" ] ]);
```