Revert "DynamoDBToS3Operator - Add feature to export table to a point in time

[ferruzzi]

This reverts commit fc41661.

The system test fails because it is missing the required parameter file_size, and once that is added, it fails because the table name is being passed where the API is expecting the ARN here

[utkarsharma2]

@ferruzzi @o-nikolas @vincbeck Would it make sense to introduce a new parameter for table ARN?

[ferruzzi]

If you already have the name you could look up the ARN using describe_table on the client or Table.table_arn on the resource, no need to pass both IMHO.

Mayyybe (let's see how others feel about this) add a cached property (like hook on L 136) to DynamoDBToS3Operator for table_arn that just returns client.describe_table(self.table_name)['Table']['TableArn']. That way it's only one extra API call and gets stored?