Add summary list row condition

[frankieroberto]

This wraps all of the the HTML for a summary list row in a condition which checks whether the row object is present.

This allows inline conditions within the nunjucks macro, which can be handy for prototyping, for example:

{ summaryList({
  rows: [
    {
      key: {
        text: "Name"
      },
      value: {
        text: data.name
      }
    } if data.name,
    {
      key: {
        text: "Date of birth"
      },
      value: {
        text: data.dob
      }
    } if data.dob
  ]
}) }}

See the same feature on the GOV.UK version of summary list.

I don’t think this usually gets mentioned in documentation though.

Checklist

• Tested against our testing policy (Resolution, Browser & Accessibility)
• Follows our coding standards and style guide
• CHANGELOG entry