Minor followup to #7335 (#7347)

* Unify SortWidget's pagination button (it was using a tap_input, which is why I'd missed it ;)). (https://github.com/koreader/koreader/pull/7335#issuecomment-785628495)
* Menu*: Remove redundant screen-layout updates from `_recalculateDimen`, as it should only be concerned with item layout (https://github.com/koreader/koreader/pull/7335#discussion_r582072032)

frontend/ui/widget/sortwidget.lua

@@ -296,7 +296,7 @@ function SortWidget:init()
 
     self.footer_page = Button:new{
         text = "",
-        tap_input = {
+        hold_input = {
             title = _("Enter page number"),
             type = "number",
             hint_func = function()
@@ -308,7 +308,9 @@ function SortWidget:init()
                     self:goToPage(page)
                 end
             end,
+            ok_text = "Go to page",
         },
+        call_hold_input_on_tap = true,
         bordersize = 0,
         margin = 0,
         text_font_face = "pgfont",