fix: correct catalog purchase field name and swap api method mappings

- Rename saleline_set to catalogsaleline_set in catalog purchase payload
- Fix swapped createPurchase/createCatalogPurchase method calls in Api class
- Format http.js (indentation, quotes, trailing commas)

src/pages/catalog.vue

@@ -388,7 +388,7 @@ export default {
         customer: 1,
         notes: "",
         payment_method: "CASH",
-        saleline_set: this.cartItems.map((item) => ({
+        catalogsaleline_set: this.cartItems.map((item) => ({
           product: item.id,
           unit_price: item.price,
           quantity: item.quantity,