[qa] wallet: Check if maintenance changes the balance

- [qa] Cleanup wallet.py test
- [qa] check if wallet or blochchain maintenance changes the balance
- [walletdb] Add missing LOCK() in Recover() for dummyWallet

Github-Pull: #7229
Rebased-From: fa0765d433 fa14d99484 fa33d9740c

src/wallet/walletdb.cpp

@@ -960,8 +960,13 @@ bool CWalletDB::Recover(CDBEnv& dbenv, const std::string& filename, bool fOnlyKe
             CDataStream ssKey(row.first, SER_DISK, CLIENT_VERSION);
             CDataStream ssValue(row.second, SER_DISK, CLIENT_VERSION);
             string strType, strErr;
-            bool fReadOK = ReadKeyValue(&dummyWallet, ssKey, ssValue,
+            bool fReadOK;
+            {
+                // Required in LoadKeyMetadata():
+                LOCK(dummyWallet.cs_wallet);
+                fReadOK = ReadKeyValue(&dummyWallet, ssKey, ssValue,
                                         wss, strType, strErr);
+            }
             if (!IsKeyType(strType))
                 continue;
             if (!fReadOK)