* [C++][Pistache] fix Wconversion warning
* [C++][Pistache] fix struct model compilation with std::optional
* [C++][Pistache] Add validation to struct model
* overhaul pistache templates
* fix function signature in model-source
return type now aligns with definition in model-header
* use default keyword for destructors
* generate pistache samples
* move bin/configs/other/cpp-pistache-server-cpp-pistache.yaml to bin/configs/cpp-pistache-server-cpp-pistache.yaml
* Only generate validation body if necessary
* generate pistache samples
Support basic query handling
Add helpers for primitive de-serialization
Remove warnings due to unneeded commas
Deserialize basic types in queries
Add dependencies chain for external libraries
Fixes wrong parameter passed to API