Import ElectronPhotonFourMomentumCorrection r21.2->r22

Importing ElectronPhotonFourMomentumCorrection from r21.2 -> r22

• Minimal CMakeLists.txt cleanup
• Whitespace fixes & removing editor specific characters
• Copyright -> 2020 increase

Compilation appears fine, but package not thoroughly tested yet. (tested with AB,r29 given today's nightly issues)

Tagging: @lheinric , @okiverny