ReportBuilder: Allow Named Ranges for Report Filters

When entering an Excel Named Range as a "specific items" filter for the Browsers report, ReportBuilder converts the named range to the current value of the range (e.g. '=HTML5_Browsers' to '=Sheet1!$A$2heet1!$A$30).

By allowing the Named Range to be saved in ReportBuilder, I can quickly add new cells without having to open and modify the request.