Sweeping !1159 from master to devel: feat: DataRecoveryAgent sets files to Processed in case they have descendents

@romanov @charpent this change stayed in the limbo for a (really!) long time, see also https://its.cern.ch/jira/browse/LHCBDIRAC-177 but here I decided to implement it in the simplest way. Also recently seen in https://mattermost.web.cern.ch/lhcb/pl/w8b3fat9wtnjupjd9eawkq5noe

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*Transformation CHANGE: DataRecoveryAgent sets files to Processed in case they have descendents

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