Destination-DynamoDB : keep source structure

## Tell us about the problem you're trying to solve
We need to sync snowflake to dynamodb however, wants to keep same structure as source but, connector writing entire row as json in data cloumn which is not useful.

## Describe the solution you’d like

It should mimic exact structure as source i.e column names , datatype (as supported by ddb) .

## Describe the alternative you’ve considered or used

Write a customer code and deployed in airflow to sync with snowflake to ddb

## Are you willing to submit a PR?
Yes, if it is a valid usecase for airbyte.