Facets range datepicker widget | Accessibility related cleanup

• Items (date inputs) do not have <label> tag 'for' input.
• nice to have: settings for labels, setting for visuall hidden, etc.
• *Items are not in a <form>. not sure if wrapper semantic is on the side of a11y in this context of a facet block.

items simply being in a UL isn't very useful. this can be corrected with TWIG in theme. again, a general problem with Facets.