Added selection decoration block config for CP algs
Follow up to !69110 (merged), which moved the AsgSelectionAlg run at the end of the object working point configs to schedule them as part of the OutputAnalysis config block. In order to allow for analysis-specific algorithms to be inserted before the OutputAnalysis config and rely on the decorations saved by those algorithms, a dedicated SelectionDecoration block is added, to be run before the analysis-specific algorithms.