Fixed nullable embedded types are being added to generated resolver

[Scormave]

If some embedded reference type, such as byte[] is defined as nullable in MessagePackObject, it starts to appear in generated resolver. But, generated formatter for byte[] (ArrayFormatter) is not binary compatible with embedded formatter (ByteArrayFormatter).
This is what is generated from NullableTest before the fix:

        static GeneratedResolverGetFormatterHelper()
        {
            lookup = new global::System.Collections.Generic.Dictionary<global::System.Type, int>(18)
            {
                { typeof(byte[]), 0 },
                { typeof(global::System.Collections.Generic.List<byte[]>), 1 },
                { typeof(global::System.Collections.Generic.List<global::TestData2.A>), 2 },
                { typeof(global::System.Collections.Generic.List<global::TestData2.B>), 3 },
                { typeof(int[]), 4 },
                { typeof(global::TestData2.Nest1.Id), 5 },
                { typeof(global::TestData2.Nest2.Id), 6 },
                { typeof(global::TestData2.A), 7 },
                { typeof(global::TestData2.B), 8 },
                { typeof(global::TestData2.C), 9 },
                { typeof(global::TestData2.Nest1), 10 },
                { typeof(global::TestData2.Nest1.IdType), 11 },
                { typeof(global::TestData2.Nest2), 12 },
                { typeof(global::TestData2.Nest2.IdType), 13 },
                { typeof(global::TestData2.NullableTest), 14 },
                { typeof(global::TestData2.PropNameCheck1), 15 },
                { typeof(global::TestData2.PropNameCheck2), 16 },
                { typeof(global::TestData2.Record), 17 },
            };
        }

After the fix it looks like this:

        static GeneratedResolverGetFormatterHelper()
        {
            lookup = new global::System.Collections.Generic.Dictionary<global::System.Type, int>(16)
            {
                { typeof(global::System.Collections.Generic.List<byte[]>), 0 },
                { typeof(global::System.Collections.Generic.List<global::TestData2.A>), 1 },
                { typeof(global::System.Collections.Generic.List<global::TestData2.B>), 2 },
                { typeof(global::TestData2.Nest1.Id), 3 },
                { typeof(global::TestData2.Nest2.Id), 4 },
                { typeof(global::TestData2.A), 5 },
                { typeof(global::TestData2.B), 6 },
                { typeof(global::TestData2.C), 7 },
                { typeof(global::TestData2.Nest1), 8 },
                { typeof(global::TestData2.Nest1.IdType), 9 },
                { typeof(global::TestData2.Nest2), 10 },
                { typeof(global::TestData2.Nest2.IdType), 11 },
                { typeof(global::TestData2.NullableTest), 12 },
                { typeof(global::TestData2.PropNameCheck1), 13 },
                { typeof(global::TestData2.PropNameCheck2), 14 },
                { typeof(global::TestData2.Record), 15 },
            };
        }

[AArnott]

/azp run