Manual Content: Fix all GML function pages which have empty "index" and "search" meta tags

### What is the bug?

There are two meta tags that every GML function page must have filled with its name:

```
  <meta name="rh-index-keywords" content="weak_ref_alive" />
  <meta name="search-keywords" content="weak_ref_alive" />
```

Find GML function pages that have empty 'content' for these meta tags and fill in the page name

### Where is the bug?

General