Font list menu: allow sorting by more recently set (#10662)

- Add a toggle in Font settings> allowing showing font
  ordered by most recently selected (long-press on
  it allows clearing this history).
- Keep in G_reader_settings a list of known fonts, so
  we can notice newly added user fonts, and put them
  at the start of the most recently selected. Show
  these new fonts with a symbol in the menu.
- TouchMenu: allows for a flag to trigger menu
  refresh when going up.

frontend/ui/widget/touchmenu.lua

@@ -798,6 +798,11 @@ end
 function TouchMenu:backToUpperMenu(no_close)
     if #self.item_table_stack ~= 0 then
         self.item_table = table.remove(self.item_table_stack)
+        -- Allow a menu table to refresh itself when going up (ie. from a setting
+        -- submenu that may want to have its parent menu updated).
+        if self.item_table.needs_refresh and self.item_table.refresh_func then
+            self.item_table = self.item_table.refresh_func()
+        end
         self.page = 1
         if self.parent_id then
             self:_recalculatePageLayout() -- we need an accurate self.perpage