[menu] Add optional allocator for ui menu classes (#5)

* [menu] Add optional allocator for ui menu classes, used for destroying AbstractViews

* [menu] remove coupling between modm gui and modm menu view and menu

This is because the gui stuff requires colored menus
but the menu code should not have to have colored
menus. This wouldn't be an issue if we could dynamic
cast but on certain devices you can't do this.