Summary: Give BaselineRegions a GUID so we don't have to rely on matching either the name and/or start/end stations, as these can be changed by the user.

Description: Give the BaselineRegions class a baselineRegionGUID property, similar to the baselineGUID property on the Baseline class.

We are trying to "re-link" some records in an external database with the solids extracted from a corridor. At the moment, we have to rely on either the name of the region and/or its start/end stations as these are the only properties available in the API. The user could have changed either of these, but we still want to re-link to that corridor. A GUID or other similar kind of ID that is persisant to the life of that region would be very beneficial

Product and Feature: AutoCAD Civil 3D - API

Submitted By: jh_dempsey on 01/13/2021