Refactor summary component to fix lighthouse test

[rmccar]

What is the context of this PR?

Fixes: ONSdigital/design-team#219

Lighthouse tests on summary component are failing because there is more than one level of <div> inside the <dl> when only one level is valid before the <dt> and <dd> elements. This PR refactors the summary component so that there is only one <div> level between the <dl> and <dt> and <dd> elements. As part of this summary row titles needed to be changed from being marked up as a <div> to a <dt>.

The setting and testing of the ons-summary__row--has-values class was also removed as this class no longer seems to be used for anything.

How to review this PR

• Check the lighthouse tests in the github actions and see that the result for the test for the hub and spoke examples is now at least 100.
• Also run the test locally on this branch in chrome and on the main branch to see that this issue is now fixed

Checklist

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• I have linked the correct Issue

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