implemente attachemtn download route

app/lib/actions.ts

@@ -46,13 +46,14 @@ const serializeAttachment = async (billAttachment: File | null) => {
         return null;
     }
 
-    // convert the file contents to a base64 string
+    // convert the billAttachment file contents to format that can be stored in the database
     const fileContents = await billAttachment.arrayBuffer();
     const fileContentsBase64 = Buffer.from(fileContents).toString('base64');
 
+
     // create an object to store the file in the database
     return({
-        fileName: decodeURIComponent(fileName),
+        fileName,
         fileSize,
         fileType,
         fileLastModified,