Add transaction hash to API resposnes where it is available in data node DB already

[barnabee]

In data node, many tables are already populated with the transaction hash of the relevant transaction that created/updated the record. For example, transfers.

This ticket is for the low-hanging fruit:

• [ ] Identify tables already containing a transaction hash
• [ ] Identify (REST, GraphQL) APIs returning data from those tables
• [ ] Add the transaction hash to the responses from these APIs

This would be incredibly helpful to:

• Link between pages and areas in block explorer
• Link from Console and the governance dapp to block explorer
• Help users using APIs to investigate on-chain activity to connect data together

It would be good to get an understanding of how much work this would be and if it could be added fairly quickly.