[C++] Server Stub Code Generator based on Pistache (#5838)

* Added C++ generator for Pistache

* Revert of CodegenOperation

* Updated template

* Removed isRestful from method declaration

* Updated httpMethod variable

* Changed isRestfulCreate

samples/server/petstore/pistache-server/UserApiMainServer.cpp

@@ -0,0 +1,29 @@
+/**
+* Swagger Petstore
+* This is a sample server Petstore server.  You can find out more about Swagger at [http://swagger.io](http://swagger.io) or on [irc.freenode.net, #swagger](http://swagger.io/irc/).  For this sample, you can use the api key `special-key` to test the authorization filters.
+*
+* OpenAPI spec version: 1.0.0
+* Contact: apiteam@swagger.io
+*
+* NOTE: This class is auto generated by the swagger code generator program.
+* https://github.com/swagger-api/swagger-codegen.git
+* Do not edit the class manually.
+*/
+
+#include "pistache/endpoint.h"
+#include "pistache/http.h"
+#include "pistache/router.h"
+#include "UserApiImpl.h"
+
+using namespace io::swagger::server::api;
+
+int main() {
+    Net::Address addr(Net::Ipv4::any(), Net::Port(8080));
+
+    UserApiImpl server(addr);
+    server.init(2);
+    server.start();
+
+    server.shutdown();
+}
+