Add id to ZuoraSubscription

[shtukas]

Add the id attribute to a ZuoraSubscription which, interestingly, didn't have it. (This is preliminary work for the Zuora Orders migration for amendments).

[shtukas]

Motivation:

The new subscription Id (post amendment), is written in the DynamoTable here:

price-migration-engine/lambda/src/main/scala/pricemigrationengine/handlers/AmendmentHandler.scala

Line 213 in 86c3a80

newSubscriptionId,

(more exactly is used to make an instance of SuccessfulAmendmentResult which is then written to the table.)

We get it in the answer of the amendment call itself:

price-migration-engine/lambda/src/main/scala/pricemigrationengine/handlers/AmendmentHandler.scala

Line 179 in 86c3a80

newSubscriptionId <- Zuora.updateSubscription(subscriptionBeforeUpdate, update)

But since I will be using the new API, I would like to be able to query Zuora post calling the new API and read it from the subscription itself.