Support property_NAME in MediaQuery

[Reonekot]

As far as I can tell the SDK is missing the option filter by property_NAME, as per the API documentation. As we need that I added this to my already existing copy of the SDK (waiting on #74 to move back to the official SDK). I am considering doing a PR on it, but I'm unsure how you prefer to add this as it is a bit of an odd API IMO. So I'm running with what currently works locally and thought it better to open an issue for discussion first before finishing a PR on it.

The issue is that the Key is not static so the current ApiField attribute doesn't really fit that well. What I ended up doing is adding a new ITypeToPropertyConverter (and backing converter implementation) and special handling this in QueryDecoder.ConvertProperty(). In ConvertProperty() I pass the parameters dictionary to the converted, so the Converter is responsible for adding the parameters instead of this happening in QueryDecoder.AddParam(), so I can control the name added to the dictionary.

It does feel a bit "out of place" though IMO and I also have a bit of a hard time coming up with a proper abstraction, so right now it is only serving that one use case. It also doesn't align with methods on ITypeToStringConverter/ITypeToDictionaryConverter which is shame IMO. One solution to that would ofc. be to change those types. I basically has a method call AddParameters(), which is called instead of Convert(), like so:

else if (Activator.CreateInstance(apiField.Converter) is ITypeToPropertyConverter namePropertyConverter
    && namePropertyConverter.CanConvert(propertyInfo.PropertyType))
{
    namePropertyConverter.AddParameters(parameters, apiField.ApiName, value);
}

Thoughts on how to add this API?