Crete new API to get transaction confirmation number

[pedroferreira1]

Acceptance Criteria

• New API to get the number of blocks confirming a transaction

Motivation

Many integrations (e.g. exchanges) need to wait until a transaction has some blocks confirming it before validating the fund addition (a deposit in the exchange example). Currently, all integrations must send at least 2 requests to the full node to get this information. The main goal of this API is to facilitate these integrations allowing them to get this information with a single request to the headless wallet.