Implemented Scan card menu

src/navigation/state.rs

@@ -20,12 +20,22 @@ impl NavigationState {
         Self::default()
     }
 
-    pub fn back(&mut self) -> View {
-        let screen = self.screens.pop().unwrap();
-        if self.screens.is_empty() {
-            log::info!("last screen");
-            return screen;
+    pub fn back(&mut self) -> &View {
+        match &self.screens.len() {
+            0 => {
+                log::info!("No screens to go back to");
+                return self.screens.last().unwrap();
+            }
+            1 => {
+                log::info!("Only one screen on stack, cannot go back");
+                return self.screens.last().unwrap();
+            }
+            _ => {
+                log::info!("Going back to previous screen");
+                self.screens.pop();
+                return self.screens.last().unwrap();
+            }
+            
         }
-        self.screens.pop().unwrap()
     }
 }