wallet: migration, batch addressbook records removal

Instead of doing one db transaction per removed record,
we now batch all removals in a single db transaction.

Speeding up the process and preventing the wallet from entering
an inconsistent state when any of the intermediate writes fail.

src/wallet/wallet.cpp

@@ -2395,8 +2395,13 @@ bool CWallet::SetAddressBook(const CTxDestination& address, const std::string& s
 
 bool CWallet::DelAddressBook(const CTxDestination& address)
 {
-    const std::string& dest = EncodeDestination(address);
     WalletBatch batch(GetDatabase());
+    return DelAddressBookWithDB(batch, address);
+}
+
+bool CWallet::DelAddressBookWithDB(WalletBatch& batch, const CTxDestination& address)
+{
+    const std::string& dest = EncodeDestination(address);
     {
         LOCK(cs_wallet);
         // If we want to delete receiving addresses, we should avoid calling EraseAddressData because it will delete the previously_spent value. Could instead just erase the label so it becomes a change address, and keep the data.
@@ -4079,14 +4084,17 @@ bool CWallet::ApplyMigrationData(MigrationData& data, bilingual_str& error)
     }
 
     // Remove the things to delete in this wallet
+    WalletBatch local_wallet_batch(GetDatabase());
+    local_wallet_batch.TxnBegin();
     if (dests_to_delete.size() > 0) {
         for (const auto& dest : dests_to_delete) {
-            if (!DelAddressBook(dest)) {
+            if (!DelAddressBookWithDB(local_wallet_batch, dest)) {
                 error = _("Error: Unable to remove watchonly address book data");
                 return false;
             }
         }
     }
+    local_wallet_batch.TxnCommit();
 
     // Connect the SPKM signals
     ConnectScriptPubKeyManNotifiers();

src/wallet/wallet.h

@@ -795,6 +795,7 @@ public:
     bool SetAddressBook(const CTxDestination& address, const std::string& strName, const std::optional<AddressPurpose>& purpose);
 
     bool DelAddressBook(const CTxDestination& address);
+    bool DelAddressBookWithDB(WalletBatch& batch, const CTxDestination& address);
 
     bool IsAddressPreviouslySpent(const CTxDestination& dest) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool SetAddressPreviouslySpent(WalletBatch& batch, const CTxDestination& dest, bool used) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);