add(rpc): getblock: return transaction details with verbosity=2

[conradoplg]

Motivation

We want getblock to match zcashd. With verbosity=2 we returned a list of hashes, but a list of transaction objects is expected.

Closes #9024

Specifications & References

https://github.com/zcash/zcash/blob/99ad6fdc3a549ab510422820eea5e5ce9f60a5fd/src/rpc/blockchain.cpp#L735

Solution

If verbosity=2, call getrawtransaction for each tx in the block internally and use its output to fill the transaction details.

There are tons of fields missing in getrawtransaction, but that will be another issue. When they are filled, they will be automatically returned by getblock too.

zcashd seems to not return the heigth and confirmations fields in the transactions details inside getblock (which are indeed redundant) but I think it's harmless to return them.

Tests

Expanded existing test. Also tested manually with zcash-cli.

Follow-up Work

See #8446 for other getblock related stuff, and we'll need an issue for completing getrawtransaction

PR Author's Checklist

• The PR name will make sense to users.
• The PR provides a CHANGELOG summary.
• The solution is tested.
• The documentation is up to date.
• The PR has a priority label.

PR Reviewer's Checklist

• The PR Author's checklist is complete.
• The PR resolves the issue.

[oxarbitrage]

Looks good, it might conflict with #9049

[oxarbitrage]

Suggested change

	/// A Transaction object as returnedb by `getrawtransaction` RPC request.
	/// A Transaction object as returned by `getrawtransaction` RPC request.

[oxarbitrage]

It seems some test is still locked somewhere. I am unsure if it is caused by this code but it seems so.

[arya2]

This looks good, I opened a suggestion PR (#9084) for reducing db queries and service calls.