MainServicesCfg: Set up ValkyrieProfilerSvc if requested via flag

Walter Lamplrequested to merge
wlampl/athena:ValkyrieInMainServices into 23.0

Simplify the usage of ValkyrieProfilerSvc: Add this service to the job if at least one algorithm is added to flags.PerfMon.ProfiledAlgs.

The ValkyrieProfilerSvc allows to run the profiler callgrind only on one (or some) algorithms.

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