Non-Touch: improve bottom menu usability (#8712)

- FocusManager: allow managing sub widgets by merging their
  "layout" in the main one; make "press" support simpler by
  handling it as a fake tap event at the center of the
  focused widget.
- Setup gestures on non-touch devices for new focus manager.
- ToggleSwitch: use child layout.
- ButtonProgressWidget: use child layout.
- SpinWidget and DoubleSpinWidget: add keyboard navigation.

frontend/apps/reader/modules/readerconfig.lua

@@ -26,9 +26,7 @@ function ReaderConfig:init()
             ShowConfigMenu = { {{"Press","AA"}}, doc = "show config dialog" },
         }
     end
-    if Device:isTouchDevice() then
-        self:initGesListener()
-    end
+    self:initGesListener()
     if G_reader_settings:has("activate_menu") then
         self.activation_menu = G_reader_settings:readSetting("activate_menu")
     else