Wrap component text with <p> where semantics are missing

[colinrotherham]

The Inset text and Panel components are styled <div> tags.

Plain text via params.text should be wrapped with <p></p> to improve semantics, and it's better to have sensible defaults than to assume developers will use params.html.

I've also included a fix for Warning text but due to enclosing <strong> and <span> it's a slightly different fix to the other two.

Fixes #1611 and alphagov/govuk-design-system#822

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After

[NickColley]

Thanks for jumping on this, I believe there may be other components (such as accordions), that we would want to consider this.

I've put the awaiting triage label on this so the GOV.UK Design System team can get together and decide if this is the direction we want to go in.

[colinrotherham]

Thanks @NickColley.

Good point about the accordion, I've pushed again with the same applies to its "content" divs!

Consider this a proof of concept, see what you all think 😊

[hannalaakso]

We've added #1611 to our list of Accessibility Improvements for GOV.UK Frontend under "Could" as we're not sure yet if this is the correct approach. Thanks for raising @colinrotherham 👍

[hannalaakso]

As this would be a breaking change we're not able to merge this right now. We would like to look at this but will have to wait until we release GOV.UK Frontend 4.0 which is not yet imminent.

Thanks for all your work on this @colinrotherham we'll use this PR as the basis of exploring this for 4.0. We're going to close this PR and have added the issue you raised to the 4.0 milestone.