fix: #3631109 Search page: Date Published radios like the facet lists, and a full-width keyword field on phones

Follow-up to #3631109 (issue: https://www.drupal.org/i/3631109).

Date Published in the search filter rail becomes radio buttons (horizonaid, #3631112). This styles them like the facet checkbox lists above them, scoped to the rail date block: no card border or empty legend strip, the same label size, colour and line height, the same 29px row step and the same input and label positions.

Tested on a Varbase 11 site with Horizon Aid at 1440 and 390: radios and facet checkboxes line up exactly, choosing Past Week filters and keeps the keyword, no console errors. Only views-exposed-filters.scss and its compiled CSS change.

Merge this before the horizonaid MR for #3631112.

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