rpc: Document all aliases for first arg of listtransactions

test/functional/wallet_listtransactions.py

@@ -97,6 +97,8 @@ class ListTransactionsTest(BitcoinTestFramework):
         txid = self.nodes[1].sendtoaddress(multisig["address"], 0.1)
         self.nodes[1].generate(1)
         self.sync_all()
+        assert_equal(len(self.nodes[0].listtransactions(label="watchonly", include_watchonly=True)), 1)
+        assert_equal(len(self.nodes[0].listtransactions(dummy="watchonly", include_watchonly=True)), 1)
         assert len(self.nodes[0].listtransactions(label="watchonly", count=100, include_watchonly=False)) == 0
         assert_array_result(self.nodes[0].listtransactions(label="watchonly", count=100, include_watchonly=True),
                             {"category": "receive", "amount": Decimal("0.1")},