[draft] Pilot manager legacy adaptor

[fstagni]

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[aldbr]

@AcquaDiGiorgio you can have a look at this one too

[AcquaDiGiorgio]

Okay so I based my PR on the changes made by Robin at #8233, which seem to be based on this one, so in turn I've already used these changes. In general, my PR is quite similar to this one, with getPilots implemented and a couple of other minor changes.

In addition, this PR seems to have the same problem as mine about obtaining the jobs of a pilot. selectPilots calls self.getJobsForPilotByStamp(pilotStamp) but this function is not implemented. I guess this was the skeleton for a later implementation that never came. Maybe for the same reason?

Just one question, is adding the pilotStamp to the DB, Agent and Service required for the simplification part of the migration? Shouldn't we maintain the current functionality and try to adpat to DiracX?