Inconsistency for Radio Button Toggles

[nataliecarey]

Problem

Currently there's an incompatibility between the markup in Form Elements and the required markup for toggle.js (3.2.2 and 4.2.2)

By fixing the style we break the behaviour and visa-versa.

Expected behaviour

The javascript behaviour should be compatible with the correctly styled elements

Proposed solution

The toggle should be:

• Changed to only support the new markup
• Changed to support the new markup and the old markup
• Deprecated in favour of something else

[adamliptrot-oc]

Thanks @matcarey . I suggest we mark the toggle.js as deprecated and instead advise use of the Frontend Toolkit's showhide-content.js
https://github.com/alphagov/govuk_frontend_toolkit/blob/master/javascripts/govuk/show-hide-content.js