Make SeedToTrackConversionTool thread-safe.
- SeedoTrackConversionTool is now a private tool of SiTrackMaker.
- Use WriteDataHandle instead of direct StoreGate access.
- Output data are now recorded into separate containers with names of
InDetKeys.SiSPSeedSegments()+NewTrackingCuts.extension() - Define EventData struct to hold event dependent data.
- Hold caches of EventData based on EventContext.
- Make all methods of SeedToTrackConversionTool const.