Add support for ltNEGATIVE_UNL (#1474)

Fixed #1369

src/util/LedgerUtils.cpp

@@ -68,6 +68,7 @@ static std::unordered_map<std::string, LedgerTypeAttributes> const LEDGER_TYPES_
      LedgerTypeAttributes(ripple::ltXCHAIN_OWNED_CREATE_ACCOUNT_CLAIM_ID, true)},
     {JS(did), LedgerTypeAttributes(ripple::ltDID)},
     {JS(oracle), LedgerTypeAttributes(ripple::ltORACLE)},
+    {JS(nunl), LedgerTypeAttributes(ripple::ltNEGATIVE_UNL)},
 }};
 }  // namespace impl
 

tests/unit/util/LedgerUtilsTests.cpp

@@ -51,7 +51,8 @@ TEST(LedgerUtilsTests, LedgerObjectTypeList)
         JS(xchain_owned_claim_id),
         JS(xchain_owned_create_account_claim_id),
         JS(did),
-        JS(oracle)
+        JS(oracle),
+        JS(nunl)
     };
     ASSERT_TRUE(std::size(typesList) == types.size());
     EXPECT_TRUE(std::all_of(std::cbegin(typesList), std::cend(typesList), [&types](auto const& type) {