Improve the date input component

[timpaul]

What

Make various improvements to the accessibility and usability of the date input component.

Why

This work forms part of our continuous improvement mission. The date input component is one of our most used and we have numerous outstanding stories and issues relating to it.

Stories

• Investigate removing role=“group” from date input fieldset HTML validation error: 'The group role is unnecessary for element fieldset' in date input #1590
• date-input: id documented as optional but required to create hintId and errorId
  date-input: id is documented as optional but used as required to create hintId and errorId #1557
• Investigate alternative to [type=number] for the date input component Investigate alternative to [type=number] for the date input component #1449
• NVDA not assigning labels properly in date input component NVDA not assigning labels properly in date input component #1408
• Add label or legend param to date-input Add label or legend param to date-input #1155
• Pass values to date-input when using default items Pass values to date-input when using default items #1154
• Dragon Accessibility issue with DOB field Dragon Accessibility issue with DOB field #1101
• Clarify 'Date Input' error messages Clarify 'Date Input' error messages govuk-design-system#868
• Add Dragon bug to date input guidance (close) Add Dragon bug to date input guidance govuk-design-system#782

[36degrees]

Closing this as we can now track issues related to specific components using labels. Both of the stories that are still open have the date input label.