Merge #15638: Move-only: Pull wallet code out of libbitcoin_server

4d074e84a2 [build] Move AnalyzePSBT from psbt.cpp to node/psbt.cpp (Russell Yanofsky)
fd509bd1f7 [docs] Document src subdirectories and different libraries (John Newbery)
9eaeb7fb8d [build] Move wallet load functions to wallet/load unit (John Newbery)
91a25d1e71 [build] Add several util units (John Newbery)
99517866b6 [build] Move several units into common libraries (John Newbery)
0509465542 [build] Move rpc rawtransaction util functions to rpc/rawtransaction_util.cpp (John Newbery)
1acc61f874 [build] Move rpc utility methods to rpc/util (John Newbery)
4a75c9d651 [build] Move policy settings to new src/policy/settings unit (John Newbery)
fdf8888b6f [build] Move CheckTransaction from lib_server to lib_consensus (John Newbery)

Pull request description:

  This is a move-only commit. No code is changing and the moves can be easily verified with:

  ```sh
  git log -p -n1 --color-moved=dimmed_zebra
  ```

  This commit moves functions and variables that wallet code depends on out of libbitcoin_server.a, so the bitcoin-wallet tool can be built without libbitcoin_server.a in #15639, and attempting to access server state from wallet code will result in link errors instead of silently broken code.

  List of moves:

  - `CheckTransaction` moves from `consensus/tx_verify.cpp` to `consensus/tx_check.cpp`
  - `urlDecode` moves from `httpserver.cpp` to `util/url.cpp`
  - `TransactionErrorString` moves from `node/transaction.cpp` to `util/error.cpp`
  - `StringForFeeReason` and `FeeModeFromString` move from `policy/fees.cpp` to `util/fees.cpp`
  - `incrementalRelayFee` `dustRelayFee` and `nBytesPerSigOp` move from `policy/policy.cpp` to `policy/settings.cpp`
  - `SignalsOptInRBF` moves from `policy/rbf.cpp` to `util/rbf.cpp`
  - `fIsBareMultisigStd` moves from `validation.cpp` to `policy/settings.cpp`
  - `ConstructTransaction` `TxInErrorToJSON` and `SignTransaction` move from `rpc/rawtransaction.cpp` to `rpc/rawtransaction_util.cpp`
  - `RPCTypeCheck` `RPCTypeCheckArgument` `RPCTypeCheckObj` `AmountFromValue` `ParseHashV``ParseHashO` `ParseHexV` `ParseHexO` `HelpExampleCli` and `HelpExampleRpc` move from `rpc/server.cpp` to `rpc/util.cpp`
  - `AmountHighWarn` and `AmountErrMsg` move from `ui_interface.cpp` to `util/error.cpp`
  - `FormatStateMessage` and `strMessageMagic` move from `validation.cpp` to `util/validation.cpp`
  - `VerifyWallets` `LoadWallets` `StartWallets` `FlushWallets` `StopWallets` and `UnloadWallets` move from `wallet/init.cpp` to `wallet/node.cpp`

ACKs for commit 4d074e:
  jnewbery:
    utACK 4d074e84a2 (checked by doing the rebase myself and verifying no difference between my branch and 4d074e84a2)

Tree-SHA512: 5e1604a9fb06475f2b96da0de0baa8330f4dda834dc20a0183ef11e1e4c27631d1d1bbb9abf0054efc03d56945fdf9920f63366b6a4f200f665b742a479ff75c

test/lint/lint-circular-dependencies.sh

@@ -13,7 +13,7 @@ EXPECTED_CIRCULAR_DEPENDENCIES=(
     "checkpoints -> validation -> checkpoints"
     "index/txindex -> validation -> index/txindex"
     "policy/fees -> txmempool -> policy/fees"
-    "policy/policy -> validation -> policy/policy"
+    "policy/policy -> policy/settings -> policy/policy"
     "qt/addresstablemodel -> qt/walletmodel -> qt/addresstablemodel"
     "qt/bantablemodel -> qt/clientmodel -> qt/bantablemodel"
     "qt/bitcoingui -> qt/utilitydialog -> qt/bitcoingui"
@@ -30,7 +30,7 @@ EXPECTED_CIRCULAR_DEPENDENCIES=(
     "wallet/coincontrol -> wallet/wallet -> wallet/coincontrol"
     "wallet/fees -> wallet/wallet -> wallet/fees"
     "wallet/wallet -> wallet/walletdb -> wallet/wallet"
-    "policy/fees -> policy/policy -> validation -> policy/fees"
+    "policy/fees -> txmempool -> validation -> policy/fees"
     "policy/rbf -> txmempool -> validation -> policy/rbf"
     "qt/addressbookpage -> qt/bitcoingui -> qt/walletview -> qt/addressbookpage"
     "qt/guiutil -> qt/walletmodel -> qt/optionsmodel -> qt/guiutil"