Privatize CWallet::AddToWalletIfInvolvingMe

And document in the header.

src/wallet/wallet.cpp

@@ -1028,19 +1028,6 @@ bool CWallet::LoadToWallet(const CWalletTx& wtxIn)
     return true;
 }
 
-/**
- * Add a transaction to the wallet, or update it.  pIndex and posInBlock should
- * be set when the transaction was known to be included in a block.  When
- * pIndex == nullptr, then wallet state is not updated in AddToWallet, but
- * notifications happen and cached balances are marked dirty.
- *
- * If fUpdate is true, existing transactions will be updated.
- * TODO: One exception to this is that the abandoned state is cleared under the
- * assumption that any further notification of a transaction that was considered
- * abandoned is an indication that it is not safe to be considered abandoned.
- * Abandoned state should probably be more carefully tracked via different
- * posInBlock signals or by checking mempool presence when necessary.
- */
 bool CWallet::AddToWalletIfInvolvingMe(const CTransactionRef& ptx, const CBlockIndex* pIndex, int posInBlock, bool fUpdate)
 {
     const CTransaction& tx = *ptx;