No error, when there are no items in CSV file during struct deserializing (with serde)

### Problem:
When deserializing a CSV file with only headers without any other rows into a struct (with serde), It doesn't give any error, and the records count is 0.

In this case, it may give an error, and can be stated that there must be at least one item in the csv file

Start by reproducing deserialization of a headers-only CSV file into a struct with serde, then trace the record-count and deserialization path in the repository. Confirm the intended behavior with the existing API and tests; done means the empty input produces an error if that requirement is accepted, with coverage for the headers-only case.

Written by the indexing model from the issue text.