ev-view.c: keep cursor visible when changing pages

When zoomed in in non-continuous mode, the caret cursor is sometimes not
visible after moving it to the next or previous page with the up and
down arrow keys.

Call `ensure_rectangle_is_visible` when changing to the next page, not
only when changing to the previous page. Adjust `rect` for the
coordinate difference between the window and the view's scrolling
position.
Status Job ID Name Coverage
  Build
passed #128185
flatpak

00:07:57

manual #128184
allowed to fail manual
gtk-doc
passed #128183
master

00:06:34