TinyETL: Investigate `Failed to insert batch: error returned from database`

## Backlog

Investigate and dispatch this error accordingly. Is it originating from TinyETL or from CrateDB?

## Problem

When attempting to import the file [churn-dataset.csv] into CrateDB, the procedure fails.

[churn-dataset.csv]: https://cdn2.crate.io/downloads/datasets/cratedb-datasets/machine-learning/automl/churn-dataset.csv

```shell
tinyetl \
"https://cdn2.crate.io/downloads/datasets/cratedb-datasets/machine-learning/automl/churn-dataset.csv" \
"postgresql://crate:crate@localhost/testdrive#churn"
```
```text
ERROR tinyetl: Transfer failed: Data transfer error: Failed to insert batch: error returned from database:
readerIndex: 1315907160, writerIndex: 215335 (expected: 0 <= readerIndex <= writerIndex <= capacity(215335))
```

## References
- https://github.com/crate/cratedb-examples/pull/1285#pullrequestreview-3687306741