Merge bitcoin#25849: refactor: Remove not needed empty RPC doc std::string

fac09f4 refactor: Remove not needed empty RPC doc std::string (MacroFake)

Pull request description:

  Not sure why this was put there, so remove it

ACKs for top commit:
  aureleoules:
    ACK fac09f4.

Tree-SHA512: 7fae9c612dbb82db39e3dc6e20cc7d0c8128f4abf27e34f4854f908dc1bf3ad48ebee2dbbb864a9ce95e98c5d57119bf976793945a2084a43d137c2d95a25ea1

Author: fanquake

src/wallet/rpc/spend.cpp

@@ -134,8 +134,8 @@ RPCHelpMan sendtoaddress()
                     {"use_is", RPCArg::Type::BOOL, RPCArg::Default{false}, "Deprecated and ignored"},
                     {"use_cj", RPCArg::Type::BOOL, RPCArg::Default{false}, "Use CoinJoin funds only"},
                     {"conf_target", RPCArg::Type::NUM, RPCArg::DefaultHint{"wallet -txconfirmtarget"}, "Confirmation target in blocks"},
-                    {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"unset"}, std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
-                    "       \"" + FeeModes("\"\n\"") + "\""},
+                    {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"unset"}, "The fee estimate mode, must be one of (case insensitive):\n"
+                          "\"" + FeeModes("\"\n\"") + "\""},
                     {"avoid_reuse", RPCArg::Type::BOOL, RPCArg::Default{true}, "(only available if avoid_reuse wallet flag is set) Avoid spending from dirty addresses; addresses are considered\n"
                                          "dirty if they have previously been used in a transaction."},
                     {"fee_rate", RPCArg::Type::AMOUNT, RPCArg::DefaultHint{"not set, fall back to wallet fee estimation"}, "Specify a fee rate in " + CURRENCY_ATOM + "/B."},
@@ -246,8 +246,8 @@ RPCHelpMan sendmany()
                     {"use_is", RPCArg::Type::BOOL, RPCArg::Default{false}, "Deprecated and ignored"},
                     {"use_cj", RPCArg::Type::BOOL, RPCArg::Default{false}, "Use CoinJoin funds only"},
                     {"conf_target", RPCArg::Type::NUM, RPCArg::DefaultHint{"wallet -txconfirmtarget"}, "Confirmation target in blocks"},
-                    {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"unset"}, std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
-            "       \"" + FeeModes("\"\n\"") + "\""},
+                    {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"unset"}, "The fee estimate mode, must be one of (case insensitive):\n"
+                    "\"" + FeeModes("\"\n\"") + "\""},
                     {"fee_rate", RPCArg::Type::AMOUNT, RPCArg::DefaultHint{"not set, fall back to wallet fee estimation"}, "Specify a fee rate in " + CURRENCY_ATOM + "/B."},
                     {"verbose", RPCArg::Type::BOOL, RPCArg::Default{false}, "If true, return extra information about the transaction."},
                 },
@@ -361,8 +361,8 @@ static std::vector<RPCArg> FundTxDoc()
 {
     return {
         {"conf_target", RPCArg::Type::NUM, RPCArg::DefaultHint{"wallet -txconfirmtarget"}, "Confirmation target in blocks"},
-        {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"unset"}, std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
-            "         \"" + FeeModes("\"\n\"") + "\""},
+        {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"unset"}, "The fee estimate mode, must be one of (case insensitive):\n"
+                     "\"" + FeeModes("\"\n\"") + "\""},
         {"solving_data", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED_NAMED_ARG, "Keys and scripts needed for producing a final transaction with a dummy signature.\n"
             "Used for fee estimation during coin selection.",
          {
@@ -820,8 +820,8 @@ RPCHelpMan send()
                 },
             },
             {"conf_target", RPCArg::Type::NUM, RPCArg::DefaultHint{"wallet -txconfirmtarget"}, "Confirmation target in blocks"},
-            {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"unset"}, std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
-                        "       \"" + FeeModes("\"\n\"") + "\""},
+            {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"unset"}, "The fee estimate mode, must be one of (case insensitive):\n"
+                               "\"" + FeeModes("\"\n\"") + "\""},
             {"fee_rate", RPCArg::Type::AMOUNT, RPCArg::DefaultHint{"not set, fall back to wallet fee estimation"}, "Specify a fee rate in " + CURRENCY_ATOM + "/B."},
             {"options", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED_NAMED_ARG, "",
                 Cat<std::vector<RPCArg>>(