Remove use of CCoinsViewMemPool::GetCoin in wallet code

This commit does not change behavior.

src/interfaces/chain.cpp

@@ -9,6 +9,7 @@
 #include <interfaces/handler.h>
 #include <interfaces/wallet.h>
 #include <net.h>
+#include <node/coin.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
 #include <policy/rbf.h>
@@ -287,6 +288,7 @@ public:
         }
         return true;
     }
+    void findCoins(std::map<COutPoint, Coin>& coins) override { return FindCoins(coins); }
     double guessVerificationProgress(const uint256& block_hash) override
     {
         LOCK(cs_main);

src/interfaces/chain.h

@@ -19,6 +19,7 @@ class CFeeRate;
 class CRPCCommand;
 class CScheduler;
 class CValidationState;
+class Coin;
 class uint256;
 enum class RBFTransactionState;
 struct CBlockLocator;
@@ -168,6 +169,11 @@ public:
         int64_t* time = nullptr,
         int64_t* max_time = nullptr) = 0;
 
+    //! Look up unspent output information. Returns coins in the mempool and in
+    //! the current chain UTXO set. Iterates through all the keys in the map and
+    //! populates the values.
+    virtual void findCoins(std::map<COutPoint, Coin>& coins) = 0;
+
     //! Estimate fraction of total transactions verified if blocks up to
     //! the specified block hash are verified.
     virtual double guessVerificationProgress(const uint256& block_hash) = 0;