fetchCustomersTableItems = async ({ tableName }) => {
  const rawItems = await pager.fetchItemsInDynamoDbTable({
    dynamoDbClient: exports.dynamoDbClient,
    tableName,
    extraParams: {
      Limit: 2,
      ProjectionExpression: 'Id, UserPoolId, ApiKeyId'
    }
  })
  return rawItems.map(item => ({
    identityPoolId: item.Id.S,
    userPoolId: item.UserPoolId.S,
    apiKeyId: item.ApiKeyId.S
  }))
}
Fetches all items from the CustomersTable, unwrapping DDB's datatype marker.