wallet: Add m_cached_from_me to cache "from me" status

m_cached_from_me is used to track whether a transaction is "from me", i.e. has
any inputs which belong to the wallet. This is held in memory only in
the same way that a transaction's balances are.

Author: achow101

src/wallet/receive.cpp

@@ -195,7 +195,10 @@ void CachedTxGetAmounts(const CWallet& wallet, const CWalletTx& wtx,
 
 bool CachedTxIsFromMe(const CWallet& wallet, const CWalletTx& wtx)
 {
-    return (CachedTxGetDebit(wallet, wtx, /*avoid_reuse=*/false) > 0);
+    if (!wtx.m_cached_from_me.has_value()) {
+        wtx.m_cached_from_me = wallet.IsFromMe(*wtx.tx);
+    }
+    return wtx.m_cached_from_me.value();
 }
 
 // NOLINTNEXTLINE(misc-no-recursion)

src/wallet/transaction.h

@@ -232,6 +232,8 @@ class CWalletTx
      * CWallet::ComputeTimeSmart().
      */
     unsigned int nTimeSmart;
+    // Cached value for whether the transaction spends any inputs known to the wallet
+    mutable std::optional<bool> m_cached_from_me{std::nullopt};
     int64_t nOrderPos; //!< position in ordered transaction list
     std::multimap<int64_t, CWalletTx*>::const_iterator m_it_wtxOrdered;
 
@@ -339,6 +341,7 @@ class CWalletTx
         m_amounts[CREDIT].Reset();
         fChangeCached = false;
         m_is_cache_empty = true;
+        m_cached_from_me = std::nullopt;
     }
 
     /** True if only scriptSigs are different */