Also, this response body could be a bit more informative, maybe:

- `total_processed` - this makes it known to the client that the correct number of variants were processed (trust)
- `match_count` - count of variants that matched (this arguably not needed since if there are errors it's irrelevant since it's all or nothing and if it's successfully loaded, `total_processed` is the count)
- `unknown` - array of variants that did not match (renamed from `noResults`)
- `invalid` - list of rows indices that have invalid data such as parse issues