Add PubKeyDestination for P2PK scripts

P2PK scripts are not PKHash destinations, they should have their own
type.

This also results in no longer showing a p2pkh address for p2pk outputs.
However for backwards compatibility, ListCoinst will still do this
conversion.

src/test/fuzz/script.cpp

@@ -149,13 +149,16 @@ FUZZ_TARGET(script, .init = initialize_script)
         const CTxDestination tx_destination_2{ConsumeTxDestination(fuzzed_data_provider)};
         const std::string encoded_dest{EncodeDestination(tx_destination_1)};
         const UniValue json_dest{DescribeAddress(tx_destination_1)};
-        Assert(tx_destination_1 == DecodeDestination(encoded_dest));
         (void)GetKeyForDestination(/*store=*/{}, tx_destination_1);
         const CScript dest{GetScriptForDestination(tx_destination_1)};
         const bool valid{IsValidDestination(tx_destination_1)};
-        Assert(dest.empty() != valid);
 
-        Assert(valid == IsValidDestinationString(encoded_dest));
+        if (!std::get_if<PubKeyDestination>(&tx_destination_1)) {
+            // Only try to round trip non-pubkey destinations since PubKeyDestination has no encoding
+            Assert(dest.empty() != valid);
+            Assert(tx_destination_1 == DecodeDestination(encoded_dest));
+            Assert(valid == IsValidDestinationString(encoded_dest));
+        }
 
         (void)(tx_destination_1 < tx_destination_2);
         if (tx_destination_1 == tx_destination_2) {

src/test/fuzz/util.cpp

@@ -172,6 +172,15 @@ CTxDestination ConsumeTxDestination(FuzzedDataProvider& fuzzed_data_provider) no
         [&] {
             tx_destination = CNoDestination{};
         },
+        [&] {
+            bool compressed = fuzzed_data_provider.ConsumeBool();
+            CPubKey pk{ConstructPubKeyBytes(
+                    fuzzed_data_provider,
+                    ConsumeFixedLengthByteVector(fuzzed_data_provider, (compressed ? CPubKey::COMPRESSED_SIZE : CPubKey::SIZE)),
+                    compressed
+            )};
+            tx_destination = PubKeyDestination{pk};
+        },
         [&] {
             tx_destination = PKHash{ConsumeUInt160(fuzzed_data_provider)};
         },