Some components active states are broken in compatibility mode

[NickColley]

We have run into this issue before here: #1310

This seems to be a problem for other components too, you can see the impact live on GOV.UK: https://www.gov.uk/register-to-vote

You can reproduce this by going to:
http://localhost:3000/components/button/start-link/preview?legacy=1

And changing the href to something unique in the example yaml file.

This may be an issue with other components too.

[NickColley]

Not sure if there's a more holistic approach we can have here.

Should all hrefs get automatically be cache busted?

If we did that how do we test visited states?