CAtoGlobalWrapper: merge AthAlgSeq into TopAlg for legacy support

When using CA generators in legacy job options (e.g. via CAtoGlobalWrapper) the list of algorithms needs to be appended to the TopAlg sequence to ensure correct order with the old-style fragments that populate that sequence directly. So far this was done in each CA function.

Testing this first in master as the previous attempt in !53877 (merged) had some fallouts that were not detected by the CI. Will do a manual merge into 22.0 once ART tests do not report any problems after a few days.