Add malleable fields to transaction subscription

[Dentosal]

From @nedsalk

Subscriptions currently return receipts, but they're not the only transaction-related data that's set on the node during execution; there are others like some transaction outputs, the receipts root, etc. Would it be possible for the subscriptions to return all the data that changes on a transaction after it's executed? Currently as it stands, the TS SDK creates a transaction summary that the frontend team uses in various use cases. Without e.g. the outputs on the subscription, we have to do another call to fetch them for the summary to be complete. This need for an additional fetch diminishes the benefits of the subscription even if we read the receipts from it.

Related to FuelLabs/fuels-ts#1644