TouchMenu: tweak menu search (#9926)

- Cleanup search and animation codes, fix inconsistencies
  between animation/no-animation opening, and refreshes
  glitches on eInk.
- Show menu item on tap, with buttons to either open
  directly, or to walk there (removed earlier "Animation"
  checkbox, so the choice can be decided later).
- Move event handlers into ReaderMenu/FileManagerMenu.
- Avoid duplicated and confusing results from gestures
  and font-family submenus.

frontend/apps/reader/readerui.lua

@@ -871,11 +871,4 @@ function ReaderUI:getCurrentPage()
     end
 end
 
-function ReaderUI:onMenuSearch()
-    if not self.ui then
-        self.menu:onShowMenu()
-    end
-    self.menu.menu_container[1]:onShowMenuSearch()
-end
-
 return ReaderUI