rpc: calculate fees in getblock using BlockUndo data
Summary:
Using block undo data [...] we can now show fee information for each transaction in a block without the need for additional -txindex and/or a ton of costly lookups. For a start we'll add transaction fee information to getblock verbosity level 2. This comes at a negligible speed penalty (<1%).
Backport of core#18772.
Note that we already had a test for the getblock verbose output, so this
one is added using a more explicit name (D2589).
Depends on D12425.
Test Plan:
./test/functional/test_runner.py rpc_blockchain
Reviewers: #bitcoin_abc, sdulfari
Reviewed By: #bitcoin_abc, sdulfari
Differential Revision: https://reviews.bitcoinabc.org/D12427