[rpc] add getprioritisedtransactions

This allows the user to see prioritisation for not-in-mempool
transactions.

doc/release-notes-27501.md

@@ -0,0 +1,3 @@
+- A new `getprioritisedtransactions` RPC has been added. It returns a map of all fee deltas created by the
+  user with prioritisetransaction, indexed by txid. The map also indicates whether each transaction is
+  present in the mempool.

src/rpc/mining.cpp

@@ -480,6 +480,40 @@ static RPCHelpMan prioritisetransaction()
     };
 }
 
+static RPCHelpMan getprioritisedtransactions()
+{
+    return RPCHelpMan{"getprioritisedtransactions",
+        "Returns a map of all user-created (see prioritisetransaction) fee deltas by txid, and whether the tx is present in mempool.",
+        {},
+        RPCResult{
+            RPCResult::Type::OBJ_DYN, "prioritisation-map", "prioritisation keyed by txid",
+            {
+                {RPCResult::Type::OBJ, "txid", "", {
+                    {RPCResult::Type::NUM, "fee_delta", "transaction fee delta in satoshis"},
+                    {RPCResult::Type::BOOL, "in_mempool", "whether this transaction is currently in mempool"},
+                }}
+            },
+        },
+        RPCExamples{
+            HelpExampleCli("getprioritisedtransactions", "")
+            + HelpExampleRpc("getprioritisedtransactions", "")
+        },
+        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
+        {
+            NodeContext& node = EnsureAnyNodeContext(request.context);
+            CTxMemPool& mempool = EnsureMemPool(node);
+            UniValue rpc_result{UniValue::VOBJ};
+            for (const auto& delta_info : mempool.GetPrioritisedTransactions()) {
+                UniValue result_inner{UniValue::VOBJ};
+                result_inner.pushKV("fee_delta", delta_info.delta);
+                result_inner.pushKV("in_mempool", delta_info.in_mempool);
+                rpc_result.pushKV(delta_info.txid.GetHex(), result_inner);
+            }
+            return rpc_result;
+        },
+    };
+}
+
 
 // NOTE: Assumes a conclusive result; if result is inconclusive, it must be handled by caller
 static UniValue BIP22ValidationResult(const BlockValidationState& state)
@@ -1048,6 +1082,7 @@ void RegisterMiningRPCCommands(CRPCTable& t)
         {"mining", &getnetworkhashps},
         {"mining", &getmininginfo},
         {"mining", &prioritisetransaction},
+        {"mining", &getprioritisedtransactions},
         {"mining", &getblocktemplate},
         {"mining", &submitblock},
         {"mining", &submitheader},

src/test/fuzz/rpc.cpp

@@ -134,6 +134,7 @@ const std::vector<std::string> RPC_COMMANDS_SAFE_FOR_FUZZING{
     "getnetworkinfo",
     "getnodeaddresses",
     "getpeerinfo",
+    "getprioritisedtransactions",
     "getrawmempool",
     "getrawtransaction",
     "getrpcinfo",