Add getCoinbaseMerklePath() to Mining interface

src/interfaces/mining.h

@@ -42,6 +42,13 @@ public:
     virtual CTransactionRef getCoinbaseTx() = 0;
     virtual std::vector<unsigned char> getCoinbaseCommitment() = 0;
     virtual int getWitnessCommitmentIndex() = 0;
+
+    /**
+     * Compute merkle path to the coinbase transaction
+     *
+     * @return merkle path ordered from the deepest
+     */
+    virtual std::vector<uint256> getCoinbaseMerklePath() = 0;
 };
 
 //! Interface giving clients (RPC, Stratum v2 Template Provider in the future)