Smartfactors refactor phase 4

[Frank Dellaert]

Some issues are still unresolved in the smart factors:

• Remove SmartProjectionCameraFactor and SmartProjectionPoseFactor (push everything down), harmonize handling of linearization
• Rename SmartProjectionFactor into SmartPinholeFactor
• Revive SmartProjectionCameraFactor as a typedef, to maintain header compatibility
• Revive SmartProjectionPoseFactor to maintain ASPN/Ag... compatibility, but based SmartPinholePose (Values contains Poses): after the rename, bring them back from the repo and make work again with refactored code.

[Frank Dellaert]

This is mostly done, except @lucacarlone or perhaps @cbeall3 needs to get smartfactors-ceres project compiling before merge-worthy.