DS-456, DS-469, DS-511 Windows High Contrast defects

[jsutcliffe]

DS-456 Details support for Windows High Contrast DS-479 Pagination component Windows High Contrast support DS-511 Miscellaneous Windows High Contrast defects

Specific items addressed:

Article aside: no top border Card: cards should have a border Category item: no left border Contact details: no top border Content nav: horizontal line on each item missing

• also removed "-" from pseudocontent because screen readers announced it unhelpfully Date picker: focused date outline can be partially obscured by adjacent disabled dates Details: open/close icon missing Notification banner: add a separator Pagination: current page no bottom border Phase banner: add a separator Search result: highlighted term () is black text on black background Search result: parent link no left border Side nav: selected item no left border Side nav: third level daft wee bar not visible Site header: no top border Site nav: selected item no bottom border Task list: inconsistent presentation of status (all should have border) Warning text: add border around "!" icon

[dkindnes]

Rebased locally to resolve conflicts. Main now updated.