Merge #15778: [wallet] Move maxtxfee from node to wallet

5c759c73b2 [wallet] Move maxTxFee to wallet (John Newbery)

Pull request description:

  Closes #15355

  Moves the `-maxtxfee` from the node to the wallet. See discussion in issue for details.

  This is a cleanup. There is no change in behaviour.

  Completes #15620

ACKs for commit 5c759c:
  MarcoFalke:
    utACK 5c759c73b2
  ryanofsky:
    utACK 5c759c73b2. Changes since last review: updated commit message and an error message and method name.
  meshcollider:
    utACK 5c759c73b2

Tree-SHA512: 2f9b2729da3940a5cda994d3f3bc11ee1a52fcc1c5e9842ea0ea63e4eb0300e8416853046776311298bc449ba07554aa46f0f245ce28598a5b0bd7347c12e752

src/interfaces/chain.cpp

@@ -325,7 +325,6 @@ public:
     CFeeRate relayMinFee() override { return ::minRelayTxFee; }
     CFeeRate relayIncrementalFee() override { return ::incrementalRelayFee; }
     CFeeRate relayDustFee() override { return ::dustRelayFee; }
-    CAmount maxTxFee() override { return ::maxTxFee; }
     bool getPruneMode() override { return ::fPruneMode; }
     bool p2pEnabled() override { return g_connman != nullptr; }
     bool isReadyToBroadcast() override { return !::fImporting && !::fReindex && !IsInitialBlockDownload(); }