Remove L0 from Calo digitisation
Remove L0 from Calo digitisation. Necessary following LHCb!2735 (merged). Some L0-related SPD/PRS functionality removed from CaloPinDigitAlg.
It is not clear to me whether CaloDigitAlg still does something useful. To be revised by Calo experts.
In addition, .gitignore is updated (by copying it from LHCb) and tests use a unique DatasetName to avoid problems when running them in parallel.
Edited by Rosen Matev