This MR fixes the output file merging step for hybrid AthenaMP/MT RAWtoALL with ComponentAccumulator as discussed in ATLASRECTS-7570 and is a follow-up to the MRs !61701 (merged) and !61903 (merged)
The code introduces the new file Reconstruction/RecJobTransforms/python/MergePool_Skeleton.py as the CA equivalent replacement of Reconstruction/RecJobTransforms/share/skeleton.MergePool_tf.py and is largely based on Reconstruction/RecJobTransforms/python/AODMerge_Skeleton.py.
Tagging @tsulaia for info.