Merge bitcoin/bitcoin#33819: mining: getCoinbase() returns struct instead of raw tx

48f57bb35b mining: add new getCoinbaseTx() returning a struct (Sjors Provoost)
d59b4cdb57 mining: rename getCoinbaseTx() to ..RawTx() (Sjors Provoost)

Pull request description:

  The first commit renames `getCoinbaseTx()` to `getCoinbaseRawTx()` to reflect that it returns a serialised transaction. This does not impact IPC clients, because they do not use the function name.

  The second commit then introduces a replacement `getCoinbase()` that provides a struct with everything clients need to construct a coinbase. This avoids clients having to parse and manipulate our dummy transaction.

  Deprecate but don't remove `getCoinbaseRawTx()`, `getCoinbaseCommitment()` and `getWitnessCommitmentIndex()`.

  After this change we can drop these deprecated methods, which in turn would allow us to clear the dummy transaction from the `getBlock()` result. But that is left for a followup to keep this PR focussed. See https://github.com/Sjors/bitcoin/pull/106 for an approach.

  Expand the `interface_ipc.py` functional test to document its usage.

  Can be tested using:
  - https://github.com/stratum-mining/sv2-tp/pull/59

ACKs for top commit:
  ryanofsky:
    Code review ACK 48f57bb35b. Just rebased and addressed comments and dropped coinbase tx "template" suffix, which is a nice change
  ismaelsadeeq:
    code review ACK 48f57bb35b
  vasild:
    ACK 48f57bb35b

Tree-SHA512: c4f1d752777fb3086a1a0b7b8b06e4205dbe2f3adb41f218855ad1dee952adccc263cf82acd3bf9300cc83c2c64cebd2b27f66a69beee32d325b9a85e3643b0d

src/node/interfaces.cpp

@@ -84,6 +84,7 @@ using interfaces::WalletLoader;
 using kernel::ChainstateRole;
 using node::BlockAssembler;
 using node::BlockWaitOptions;
+using node::CoinbaseTx;
 using util::Join;
 
 namespace node {
@@ -888,11 +889,16 @@ public:
         return m_block_template->vTxSigOpsCost;
     }
 
-    CTransactionRef getCoinbaseTx() override
+    CTransactionRef getCoinbaseRawTx() override
     {
         return m_block_template->block.vtx[0];
     }
 
+    CoinbaseTx getCoinbaseTx() override
+    {
+        return m_block_template->m_coinbase_tx;
+    }
+
     std::vector<unsigned char> getCoinbaseCommitment() override
     {
         return m_block_template->vchCoinbaseCommitment;