Basic Cart functionality

Add test-api function for contact page

front/src/lib/cart.ts

@@ -0,0 +1,43 @@
+import { get, writable } from "svelte/store";
+
+// Load content from localstorage
+let local = [];
+try {
+    local = JSON.parse(localStorage.getItem("basket")) || []
+} catch {
+    console.error("Failed to load cart")
+}
+
+// Store function
+function createCartStore() {
+    const cart = writable(local);
+
+    function addToCart(item: any) {
+        cart.update((cart) => [...cart, item]);
+    }
+
+    function getLength() {
+        return get(cart).length;
+    }
+
+    function removeByUUID(uuid: string) {
+        cart.update((cart) => cart.filter((item) => item.uuid !== uuid))
+    }
+
+    return {
+        ...cart,
+        addToCart,
+        getLength,
+        removeByUUID,
+    }
+}
+
+// Create store
+const Cart = createCartStore();
+
+// Make sure to update localstorage on any changes
+Cart.subscribe((value) => {
+    localStorage.setItem("basket", JSON.stringify(value));
+});
+
+export default Cart;