[RPC] add new utxoupdatepsbt arguments to the CRPCCommand and CPRCConvertParam tables

The new `descriptors` argument needs to be added to the Command and
ConvertParams tables to by usable as a named argument and by
bitcoin-cli.

Also update the test to use named arguments to test this.

src/rpc/client.cpp

@@ -28,6 +28,7 @@ public:
 static const CRPCConvertParam vRPCConvertParams[] =
 {
     { "setmocktime", 0, "timestamp" },
+    { "utxoupdatepsbt", 1, "descriptors" },
     { "generatetoaddress", 0, "nblocks" },
     { "generatetoaddress", 2, "maxtries" },
     { "getnetworkhashps", 0, "nblocks" },

src/rpc/rawtransaction.cpp

@@ -1776,7 +1776,7 @@ static const CRPCCommand commands[] =
     { "rawtransactions",    "finalizepsbt",                 &finalizepsbt,              {"psbt", "extract"} },
     { "rawtransactions",    "createpsbt",                   &createpsbt,                {"inputs","outputs","locktime","replaceable"} },
     { "rawtransactions",    "converttopsbt",                &converttopsbt,             {"hexstring","permitsigdata","iswitness"} },
-    { "rawtransactions",    "utxoupdatepsbt",               &utxoupdatepsbt,            {"psbt"} },
+    { "rawtransactions",    "utxoupdatepsbt",               &utxoupdatepsbt,            {"psbt", "descriptors"} },
     { "rawtransactions",    "joinpsbts",                    &joinpsbts,                 {"txs"} },
     { "rawtransactions",    "analyzepsbt",                  &analyzepsbt,               {"psbt"} },
 

test/functional/rpc_psbt.py

@@ -346,7 +346,7 @@ class PSBTTest(BitcoinTestFramework):
 
         # Try again, now while providing descriptors, making P2SH-segwit work, and causing bip32_derivs and redeem_script to be filled in
         descs = [self.nodes[1].getaddressinfo(addr)['desc'] for addr in [addr1,addr2,addr3]]
-        updated = self.nodes[1].utxoupdatepsbt(psbt, descs)
+        updated = self.nodes[1].utxoupdatepsbt(psbt=psbt, descriptors=descs)
         decoded = self.nodes[1].decodepsbt(updated)
         test_psbt_input_keys(decoded['inputs'][0], ['witness_utxo', 'bip32_derivs'])
         test_psbt_input_keys(decoded['inputs'][1], [])