Add utm_campaign and other fields to the User class

[ogamaniuk]

I need to be able to set utm_campaign, utm_source and other related field using the C# library. The REST Intercom API allows that, I just rant the following HTTP request:

POST https://api.intercom.io/users HTTP/1.1
Accept-Charset: UTF-8
Accept: application/json
Authorization: Basic  
User-Agent: RestSharp/105.2.3.0
Content-Type: application/json
Host: api.intercom.io
Content-Length: 52
Accept-Encoding: gzip, deflate

{"id":"5874f28d6220b21bb424c58c","new_session":true, "utm_campaign":"test2"}

[kmossco]

Thank you for reporting this! We need to add this to the user model indeed, adding it to the roadmap so we can get it done asap.