Draft: First implementation of pixel clustering with xAOD Pixel Cluster class

First implementation of the xAOD InDetMeasurement Pixel Cluster class in pixel clusterization along side of the InDetPrepData version of Pixel Clusters. The intention is eventually change the names of the functions to be the same but with different signatures, but for now in development they are separate.

mentioned in merge request !51343 (merged)

Closed after 3 months of inactivity, as per shifter rules.

Cheers, Martin (L1)

closed