Add cheated track fit for U2

Adding cheated track fit configuration with

• new PR for Long and Downstream tracks, and track fit for them
• TrackResolutionChecker - both nTuple and Histo versions

As for now, Long fit runs fine. Upstream and Downstream fits return errors during the track fit sometimes.

Goes with Rec!3833 (merged) LHCb!4499 (merged)

@tevans