* [C++][Pistache] Replace contains with find on json object
This makes generator compatible with nlohmann-json 3.5.0
* [C++][Pistache] Update Petstore sample
* Fixed#2643
Refactored to/from json functions to use universal object serialization method.
* Code review found incorrect indenting and I forgot to remove unused mustache files.
* Removed helpers class because it is not needed anymore.
* Removed helpers package from docs.
* Reverted helper class removal.
* Added missing includes for optional
* Removed shared pointer from pistache generator
* Changed Net namespace to Pistache Namespace
* Clean up code and removed unnecessary lines in mustache files
* Removed remaining shared pointer syntax
* Code review fixes + updated samples
* Added const to all model setter functions, and reference to all params in setters that are not primitives
* Refactored modelbase
* Removed const
* Updated samples
