MM-13718 Prevent files from being attached to multiple posts (#10094)

* MM-13718 Prevent files from being attached to multiple posts

* Switch back to non-batched AttachToPost

* Change status code when failing to attach a file

app/import_functions.go

@@ -1028,7 +1028,7 @@ func (a *App) uploadAttachments(attachments *[]AttachmentImportData, post *model
 
 func (a *App) UpdateFileInfoWithPostId(post *model.Post) {
 	for _, fileId := range post.FileIds {
-		if result := <-a.Srv.Store.FileInfo().AttachToPost(fileId, post.Id); result.Err != nil {
+		if result := <-a.Srv.Store.FileInfo().AttachToPost(fileId, post.Id, post.UserId); result.Err != nil {
 			mlog.Error(fmt.Sprintf("Error attaching files to post. postId=%v, fileIds=%v, message=%v", post.Id, post.FileIds, result.Err), mlog.String("post_id", post.Id))
 		}
 	}