[UX] Add ToC/Bookmarks settings

- Menu widget: allow specifying the number of items per
  page and the item font size, so we can use other values
  than the default File browser ones
- Menu: fix setDirty when a border is used
- ToC: add item per page and font size settings, make
  Alternative ToC more visible (was previously
  available on long-press on Table of contents)
- Bookmarks: add item per page, font size, size reduction
- Progress bars (Skim widget and footer): allow selecting
  ToC depths from which ticks are made.

frontend/apps/reader/modules/readerfont.lua

@@ -169,12 +169,13 @@ function ReaderFont:onShowFontMenu()
         width = Screen:getWidth() - 100,
         height = math.floor(Screen:getHeight() * 0.5),
         single_line = true,
-        perpage_custom = 8,
+        items_per_page = 8,
+        items_font_size = Menu.getItemFontSize(8),
     }
     -- build container
     local menu_container = CenterContainer:new{
-        main_menu,
         dimen = Screen:getSize(),
+        main_menu,
     }
     main_menu.close_callback = function ()
         UIManager:close(menu_container)