Allow event scheduling for PI Point DR attributes that use RelativeTime or TimeRange

Currently it's not possible to use attributes that are based on a PI Point Data Reference with RelativeTime or TimeRange settings as triggers for analyses with event-triggered scheduling. You get the "No valid triggering inputs found" error. The reason is that this kind of configuration does not support AFDataPipe, as detailed in the first table in "Restrictions on viewing time series data". https://docs.osisoft.com/bundle/pi-server/page/restrictions-on-viewing-time-series-data.html A workaround is to create a second attribute which simply refers the same PI Point without any RelativeTime setting, and to include that in the analysis expression unobtrusively, e.g. by multiplying with 0 and adding it to the existing expression. This will ensure that the analysis gets triggered whenever a new event is received for the PI point, as desired. The workaround is a bit clumsy and might be rendered ineffective if the analysis engine gets more clever and optimizes away any part that doesn't contribute to the result. Please consider adding AFDataPipe support for these non-simple data references.