FPGATrackSimGenScan track finding updates
This contains the following closely related updates: -- turned the FPGATrackGenScanBinning class into an Athena tool so that it can be configured directly instead of passing through FPGATrackGenScanTool -- added new feature to build track working in from the outer pixels -- added new track building method which builds pairs incrementally -- also cleaned up some of the include statements based on Clang suggestions