Script link component's story doesn't match simorgh usage

[AlistairGempf]

Describe the bug
In simorgh, we use the script link component with visually hidden text of the service. We don't have the visually hidden text in the psammead story book, making it less representative when doing a11y testing in psammead.

To Reproduce
Steps to reproduce the behaviour:

1. Go to script link storybook
2. Observe the Inspector
3. Notice the lack of visually hidden text

Expected behaviour
Script link storybook should have visually hidden text.

Additional context
The script link renders all of its children, so should just be a case of adding a VisuallyHiddenText component into the story.