Add option to AddXmlDocumentationTransform to remove newlines in comments

[siegfriedpammer]

Currently Visual Studio generates the following weird-looking comment out of our multi-line XML comments. For Visual Studio it seems, it would be best to squash the whole comment into a single line.

        //
        // Summary:
        //     /// Gets or sets on premises domain name. ///
        [JsonProperty(NullValueHandling = NullValueHandling.Ignore, PropertyName = "onPremisesDomainName", Required = Required.Default)]
        public string OnPremisesDomainName
        {
            get;
            set;
        }