Update to GOVUK Frontend v4.2.0

[joelanman]

Closes #1442

This also adds the new pagination component to app/views/layout.html

I don't think the update process covers this change, we may need to think about that

The release notes mention "Replace deprecated govuk-header__link--service-name class in the header" - we have a reference to this in cypress, I'm not sure if it needs updating?

[lfdebrux]

I don't think the update process covers this change, we may need to think about that

I think we can either add to the user steps for the update process, or we could move the layout/template views into the lib folder, similar to #1388.

[joelanman]

I think it's likely some people have edited layout so I'm not sure it's safe to move it to lib or automatically update it.

For now maybe we just tell people as part of the release notes that they should add this line to app/views/layout.html if they're updating @NoraGDS, and raise an issue to look at this properly in the future

[lfdebrux]

The release notes mention "Replace deprecated govuk-header__link--service-name class in the header" - we have a reference to this in cypress, I'm not sure if it needs updating?

It's not strictly necessary, it looks like @BenSurgisonGDS already anticipated this issue and updated the code to be forwards compatible in 68cde6f

That said removing the reference to that class would make the code slightly neater, so up to you.

[lfdebrux]

WFM 👍