Switch newsletter form to SvelteKit Form Actions

- remove api endpoint and use latest SK form actions
- create reusable server page function for form handling
- handling the errors in the server function

src/routes/+page.server.ts

@@ -1,8 +1,13 @@
 import { error } from '@sveltejs/kit'
-import type { PageServerLoad } from './$types'
+import type { Actions, PageServerLoad } from './$types'
 import { fetchAPI } from '$utils/api'
 import { getRandomItems } from '$utils/functions'
+import subscribe from '$utils/forms/subscribe'
 
+
+/**
+ * Page Data
+ */
 export const load: PageServerLoad = async ({ setHeaders }) => {
     try {
         // Get total of published photos
@@ -52,4 +57,13 @@ export const load: PageServerLoad = async ({ setHeaders }) => {
     } catch (err) {
         throw error(500, err.message)
     }
+}
+
+
+/**
+ * Form Data
+ */
+ export const actions: Actions = {
+    // Form newsletter subscription
+    subscribe,
 }