extract has_position trait

src/level_widget.rs

@@ -5,6 +5,7 @@ use ratatui::widgets::{StatefulWidget, Widget};
 
 use crate::game::Game;
 use crate::level::StructureElement;
+use crate::position::HasPosition;
 
 const FG_BROWN: Color = Color::Rgb(186, 74, 0);