Merge #15779: test: Add wallet_balance benchmark

fad7c33342 refactor: Add handleNotifications method to wallet (MarcoFalke)
fa46ac3127 bench: Add wallet_balance benchmarks (MarcoFalke)

Pull request description:

ACKs for commit fad7c3:
  ryanofsky:
    utACK fad7c33342. I might squash or rearrange the commits to avoid adding code in one commit that just gets deleted in the next one. But overall this looks good and the cleanup is nice.

Tree-SHA512: 231faac168cbe9bb0ab4bf10ac1d5b042c610364406d75061fba27f1e9d16c71867e74cc4606e9f42659aa980d7133c00e29fcc18bbba7da2fa7a80178b3246c

src/test/util.cpp

@@ -22,6 +22,8 @@
 
 #include <boost/thread.hpp>
 
+const std::string ADDRESS_BCRT1_UNSPENDABLE = "bcrt1qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq3xueyj";
+
 #ifdef ENABLE_WALLET
 std::string getnewaddress(CWallet& w)
 {
@@ -75,7 +77,6 @@ CTxIn MineBlock(const CScript& coinbase_scriptPubKey)
     return CTxIn{block->vtx[0]->GetHash(), 0};
 }
 
-
 std::shared_ptr<CBlock> PrepareBlock(const CScript& coinbase_scriptPubKey)
 {
     auto block = std::make_shared<CBlock>(

src/test/util.h

@@ -13,6 +13,10 @@ class CScript;
 class CTxIn;
 class CWallet;
 
+// Constants //
+
+extern const std::string ADDRESS_BCRT1_UNSPENDABLE;
+
 // Lower-level utils //
 
 /** Returns the generated coin */