Links were the page body's only focus targets, so spatial nav jumped from
a link to the next one however far down, or straight to the toolbar, and
the text in between could not be read on the M9 (or with a d-pad).
Up/Down on the Web page now move to the next link already on screen, else
scroll the body a page (handing focus to a link coming on screen when the
focused one scrolls off); only at the end of the page does focus leave for
the address row or toolbar. navMoveDir reports when the page took the press
so the M9 and Attaky "focus did not move" fallbacks don't scroll twice.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
