use types instead of interfaces

helpers/storage.ts

@@ -1,11 +1,13 @@
+import { Booking } from '../db/booking'
+
 const BOOKING_DATA_KEY = 'pfadiBussleBookingData'
 
 function getStorage() {
   return localStorage
 }
 
-export function storeBookingData({ booker, ...booking }) {
-  const { name, email, street, zip, city } = booker
+export function storeBookingData(booking: Booking) {
+  const { name, email, street, zip, city } = booking.booker
   const { org } = booking
 
   getStorage().setItem(