Ensure search action button coalesced to adjacent input (#11385)
Fomantic-ui's action button syntax requires that the button is
the next sibling of the input it is attached to and that they
are both children of a div.action.
Fix#11375
Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: Lauris BH <lauris@nix.lv>