[http-client-csharp] `WireInformation` should also include other type of serialization information

[ArcturusZhang]

The WireInformation class now looks like this:

model WireInformation {
   SerializedName: string;
}

we use the SerializedName as the "json" serialization name, when we support xml, we might need to add something on xml in this options, because some models might both support json and xml, and xml has way more complicated serialization information than json.