[Fix] 0047066 UI: Standard filter – add aria-labelledby to region divs

[fhelfer]

Error 6881 5 The “aria-labelledby” attribute must not be specified on any “div” element unless the element has a “role” value other than “caption”, “code”, “deletion”, “emphasis”, “generic”, “insertion”, “paragraph”, “presentation”, “strong”, “subscript”, or “superscript”.
https://mantis.ilias.de/view.php?id=47066

Regions (role="region") for active inputs and section inputs must
reference their label. Set aria-labelledby="opener_{ID_FILTER}"
(resp. opener_{ID_FILTER_ACTIVE}) so screen readers associate the
expandable sections with the filter opener button.

Problem

• Accessibility: Die Bereiche mit role="region" (aktive Filter, Filter-Eingaben) hatten keine Zuordnung zum beschriftenden Element (Opener-Button).

Lösung

• In tpl.standard_filter.ht