Remove -zapwallettxes

-zapwallettxes is made a hidden option to inform users that it is
removed and they should be using abandontransaction to do the stuck
transaction thing.

src/wallet/walletdb.cpp

@@ -926,23 +926,6 @@ DBErrors WalletBatch::ZapSelectTx(std::vector<uint256>& vTxHashIn, std::vector<u
     return DBErrors::LOAD_OK;
 }
 
-DBErrors WalletBatch::ZapWalletTx(std::list<CWalletTx>& vWtx)
-{
-    // build list of wallet TXs
-    std::vector<uint256> vTxHash;
-    DBErrors err = FindWalletTx(vTxHash, vWtx);
-    if (err != DBErrors::LOAD_OK)
-        return err;
-
-    // erase each wallet TX
-    for (const uint256& hash : vTxHash) {
-        if (!EraseTx(hash))
-            return DBErrors::CORRUPT;
-    }
-
-    return DBErrors::LOAD_OK;
-}
-
 void MaybeCompactWalletDB()
 {
     static std::atomic<bool> fOneThread(false);