This lambda is used to replicate the change data capture (CDC) records
from our DynamoDB tables to their corresponding ClickHouse ones. This
is done by listening to the stream of `INSERT`, `MODIFY`, and `REMOVE`
events coming to the DynamoDB tables, extracting the documents, and upsert
them into ClickHouse

Because the JSON structure of a DynamoDB event includes some simple
datatype annotation ([link](https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_streams_AttributeValue.html)).
The lambda performs some transformation to convert it back to a regular
JSON data structure.

### Deployment

A new version of the lambda can be deployed using `make deploy` and it
is done so automatically as part of the CI in `.github/workflows/clickhouse-replicator-dynamo-lambda.yml`.
