Column generation Bin Packing heuristic based on CFT (#4639)

* Laid down outer refinement tentative integration with existing code
* Fixed Refinement design, (still figuring out a clean way to integrate it)
* Adding base object accessor function to views
* Completed `ResetToIdentitySubModel` for `CoreModel` and `SubModelView`
* Minor numerical issues strenghtening
* Time statistics
* Improved subgradient stability with numerically challenging cases
* Removed subgradient stabilization (issues with core updates)
* Forcing core update at subgradient end
* Replacing std::cout with VLOGs
* Housekeeping
* CoreUpdate more robust to potential full-model changes
* Skip CoreUpdate when columns are rougthly the same number of rows
* Full-model does not require row-view anymore
* Added cft example
* More torough `FullToSubModelInvariantCheck`
* Better management of empty columns
* Improved `FullToSubModelInvariantCheck`
* Refactored `FullToCoreModel` column selection
* Minor `FullToCoreModel` cleaning
* Refactored `FullToCoreModel` to simplify extention with column generation
* BinPacking model
* Bin Packing instance readers
* Simple best fit greedy heuristic
* Simple initial bin generation
* Bin set
* Initial work on Bin Packing - Set Cover core model generator
* Simple knapsack greedy heuristic
* Simple Branch and bound for Knapsack (from Pisinger)
* Dyamic column generation in core model update
* CFT based bin packing heuristic example
* Split initial bin generation with randomized one
* Updated `bin_packing_cft.cc` example
* Fixed some problems with BPP column generation
* Added small test to bin_packing example

Author: c4v4