Add upgrade_2018_BdKstee_LDST to TestFileDB
Add upgrade BdKstee MC sample in LDST format to TestFileDB, around 10k events are included. This is needed to setup the PRConfig and qmtest tests for electron tracking efficiencies. For the record, the following lines are needed to be able to run Brunel on this sample:
from Configurables import RecombineRawEvent
RecombineRawEvent().Version = 4.2