TrigT2CaloCalibration: Package cleanup
Delete unused T2SampCalibTool, T2CaloJetCalib_dBObj, IT2HadCalibTool, T2GSCalibTool, T2JESCalibTool.
Also some general package cleanups:
- move all private headers to src/
- change library to interface library
- cleanup link dependencies
- enable flake8
- delete obsolete files
- enable thread checker