Date filters for the NHS prototype kit

[vickytnz]

Adding date filters would help a lot with the kit, for example with consistent formatting.

The GOV.UK prototype kit uses the xgovuk-prototype kit. https://prototype-kit.service.gov.uk/docs/date-filters

This ticket is based on creating functionality first (with a separate ticket for documentation to be created as needed). However if the decision is to just use the xgovuk-prototype-filters then this will become a documentation only ticket.

Work on the more basic filters page also showed that we may want to think about which date module we use nhsuk/nhsuk.service-manual.prototype-kit.docs#158 (comment)

[vickytnz]

nhsuk/nhsuk.service-manual.prototype-kit.docs#158 (comment) mentions being able to use the Intl.DateTimeFormat api built in to JavaScript and Node without requiring a third party library