Prompt data for Bd2Dpi analysis

Tupling up some 2018 data from a time unbiased line to build a prompt D- sample by making a fake B0 candidate combining a D- candidate with a random track.

For now just using the 2018 data while I get my overall workflow sorted and then can add in the full Run 2 later. Also tupling up a MC sample just to have for comparison, for some reason it wasn't generated with both polarities but I think it'll do for now.

The script used is very similar to in previous tuplings for this analysis, just with appropriate changes for running on MDST and a slightly more general decay descriptor.