Modify Timely App datasource to interpolate or provide zero values #153
Description
In #91 we removed interpolation from the server side for performance reasons. In the U/I there is a mechanism where the user can select how to treat missing data (Null value dropdown on the Display tab). For connected, we should interpolate missing values and for null as zero we should put a zero in the missing time slot. My guess is that our behavior right now is consistent with null, but should be tested.