Add helpers and types for BFF API

lib/api/helpers/users.ts

@@ -0,0 +1,18 @@
+export async function getUsers() {
+  const response = await fetch("/api/users");
+  if (!response.ok) {
+    throw new Error(`Response status: ${response.status}`);
+  }
+
+  return response.json();
+}
+
+export async function getUser(id: number) {
+  const response = await fetch(`/api/users/${id}`);
+
+  if (!response.ok) {
+    throw new Error(`Response status: ${response.status}`);
+  }
+
+  return response.json();
+}