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# Type of request: This is a ...

[ X ] bug report
[ ] feature request

# Detailed description

On BatchWriteItem if items are throttled, we are expected to receive a list of `UnprocessedItems` in the response instead of HTTP 500

## Expected behavior

Receive HTTP 200 but with Unprocessed Items in the response: https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_BatchWriteItem.html#DDB-BatchWriteItem-response-UnprocessedItems

## Actual behavior

Receive HTTP 500 ProvisionedThroughPutException. "All or nothing"

# Steps to reproduce

Start LocalStack with DynamoDb Service and "DYNAMODB_ERROR_PROBABILITY=1.0"

## Command used to start LocalStack

```
new LocalStackContainer(DockerImageName.parse("localstack/localstack:0.12.9"))
      .withEnv("DYNAMODB_ERROR_PROBABILITY", "1.0")
      .withServices(DYNAMODB)
```

## Client code (AWS SDK code snippet, or sequence of "awslocal" commands)

You can just Randomly generate a big list of objects (exceeding 1kb per batch) and check this behaviour


if table_def.get('KinesisDataStreamDestinations'):
        if table_def['KinesisDataStreamDestinationStatus'] == 'ACTIVE':
            for dest in table_def['KinesisDataStreamDestinations']:
                if dest['StreamArn'] == data['StreamArn'] and dest['DestinationStatus'] == 'ACTIVE':
                    dest['DestinationStatus'] = 'DISABLED'
                    dest['DestinationStatusDescription'] = 'Stream is disabled',
                    table_def['KinesisDataStreamDestinationStatus'] = 'DISABLED'
                    response = aws_responses.requests_response({
                        'DestinationStatus': 'DISABLED',
                        'StreamArn': data['StreamArn'],
                        'TableName': data['TableName']
                    })
                    return response
    return error_response(
        error_type='ValidationException',
        message='Table is not in a valid state to disable Kinesis Streaming Destination:'
        'DisableKinesisStreamingDestination must be ACTIVE to perform DISABLE operation.'
    )
def error_response(message=None, error_type=None, code=400):