Merge #18842: wallet: Mark replaced tx to not be in the mempool anymore

fa4e088cba wallet: Mark replaced tx to not be in the mempool anymore (MarcoFalke)

Pull request description:

  The wallet does not mark the replaced tx as out-of-mempool. This causes failures in user scripts, because later RPCs may depend on this state change from `bumpfee`.

  For example, the following might fail on current master:

  ```
  txid = sendtoaddress(...)
  bumpfee(txid)
  abandontransaction(txid)  # fails because txid is still marked as "in mempool"
  ```

  Fixes #18831

ACKs for top commit:
  meshcollider:
    utACK fa4e088cba
  ryanofsky:
    Code review ACK fa4e088cba, and previous ACK faeedff5c87091fd83d2fb2b29eb49c948363f29 is also still valid in case there's a preference for the original fix

Tree-SHA512: 9858f40f5fb5a43a7b584b5c4268b6befa82e6a84583be5206fe721bcb6c255e8d35479d347d0b9aed72703df49887c02b14ab680e8efdd28b90dd6b93d9439a

src/node/interfaces.cpp

@@ -526,6 +526,12 @@ public:
         LOCK(m_node.mempool->cs);
         return IsRBFOptIn(tx, *m_node.mempool);
     }
+    bool isInMempool(const uint256& txid) override
+    {
+        if (!m_node.mempool) return false;
+        LOCK(m_node.mempool->cs);
+        return m_node.mempool->exists(txid);
+    }
     bool hasDescendantsInMempool(const uint256& txid) override
     {
         if (!m_node.mempool) return false;