feat: add and enhance PermitsScreen and RequestPermitModal

- add LoadingScreen component
- update utilities

components/LoadingScreen.tsx

@@ -0,0 +1,10 @@
+import { View, Text, ActivityIndicator } from 'react-native';
+
+export default function LoadingScreen() {
+    return (
+        <View className="flex-1 justify-center items-center bg-gray-50">
+            <ActivityIndicator size="large" color="#099499" />
+            <Text className="text-gray-500 mt-2">Caricamento...</Text>
+        </View>
+    );
+}