refactor: move triggerDownload function to utils

frontend/app/utils/index.ts

@@ -0,0 +1,9 @@
+export function triggerDownload(file: Blob, file_name: string) {
+    const url = window.URL.createObjectURL(file);
+    const link = document.createElement('a');
+    link.href = url;
+    link.download = `${file_name}.pdf`;
+    link.target = "_blank";
+    link.click();
+    window.URL.revokeObjectURL(url);
+}