Fix VP_cluster_monitoring tests

As reported in #880 , VELO clustering monitoring tests in RecoConf are failing after updating to more up to date input MC sample. Rec!4308 (merged) fixes the issue, however with the current defaults also the tests that should use VPClus now use RetinaClusters.

This MR updates the algorithm used for reconstruct FullClusters in the different VP_cluster_monitoring tests:

• VP_cluster_monitoring_baseline: algorithm set in default_input_and_conds_hlt1.py
• VP_cluster_monitoring_VPClus: VPClusFull
• VP_cluster_monitoring_retina: VPRetinaFullClusterDecoder

References must be updated.

FYI @msaur @dovombru @mveghel @dpassaro