/// <summary>
/// Reads a file with the given file-identifier. The method can alter the Download-Name and set the fileContent
/// </summary>
/// <param name="fileIdentifier">the identifier of the file</param>
/// <param name="downloadingIdentity">the identity that is downloading the requested file</param>
/// <param name="downloadName">the download-name of the file</param>
/// <param name="contentType">the content-type that is set in the result-header</param>
/// <param name="fileDownload">indicates whether the provided file should be served as file-download or as embeddable file-result</param>
/// <param name="fileContent">the content of the file</param>
/// <returns>a value indicating whether the file was found</returns>
public bool ReadFile(string fileIdentifier, IIdentity downloadingIdentity, ref string downloadName, ref string contentType,
ref bool fileDownload, out byte[] fileContent)
{
int colon = fileIdentifier.IndexOf(":");
string fileType = colon != -1 ? fileIdentifier.Substring(0, colon) : fileIdentifier;
var filterDic = colon != -1 ? ReadFilterDic(fileIdentifier.Substring(colon + 1)) : new Dictionary <string, int>();
object desc = handler.DescribeConfig(fileType, filterDic, out var name);
var descString = JsonHelper.ToJsonStrongTyped(desc);
fileContent = Encoding.UTF8.GetBytes(descString);
downloadName = $"{name}.json";
contentType = "application/json";
fileDownload = true;
return(true);
}