[C++ server] Adjust the names (script, sample folder, generator) to lang option (#250)

* Renamce C++ server scripts

* Change output folder

* Rename sample folder: pistache-server -> cpp-pistache

* Rename sample folder: restbed -> cpp-restbed

samples/server/petstore/cpp-pistache/model/Order.h

@@ -0,0 +1,115 @@
+/**
+* OpenAPI Petstore
+* This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+*
+* OpenAPI spec version: 1.0.0
+* 
+*
+* NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+* https://openapi-generator.tech
+* Do not edit the class manually.
+*/
+/*
+ * Order.h
+ *
+ * An order for a pets from the pet store
+ */
+
+#ifndef Order_H_
+#define Order_H_
+
+
+#include "ModelBase.h"
+
+#include <string>
+
+namespace org {
+namespace openapitools {
+namespace server {
+namespace model {
+
+/// <summary>
+/// An order for a pets from the pet store
+/// </summary>
+class  Order
+    : public ModelBase
+{
+public:
+    Order();
+    virtual ~Order();
+
+    /////////////////////////////////////////////
+    /// ModelBase overrides
+
+    void validate() override;
+
+    nlohmann::json toJson() const override;
+    void fromJson(nlohmann::json& json) override;
+
+    /////////////////////////////////////////////
+    /// Order members
+
+    /// <summary>
+    /// 
+    /// </summary>
+    int64_t getId() const;
+    void setId(int64_t value);
+    bool idIsSet() const;
+    void unsetId();
+    /// <summary>
+    /// 
+    /// </summary>
+    int64_t getPetId() const;
+    void setPetId(int64_t value);
+    bool petIdIsSet() const;
+    void unsetPetId();
+    /// <summary>
+    /// 
+    /// </summary>
+    int32_t getQuantity() const;
+    void setQuantity(int32_t value);
+    bool quantityIsSet() const;
+    void unsetQuantity();
+    /// <summary>
+    /// 
+    /// </summary>
+    std::string getShipDate() const;
+    void setShipDate(std::string value);
+    bool shipDateIsSet() const;
+    void unsetShipDate();
+    /// <summary>
+    /// Order Status
+    /// </summary>
+    std::string getStatus() const;
+    void setStatus(std::string value);
+    bool statusIsSet() const;
+    void unsetStatus();
+    /// <summary>
+    /// 
+    /// </summary>
+    bool isComplete() const;
+    void setComplete(bool value);
+    bool completeIsSet() const;
+    void unsetComplete();
+
+protected:
+    int64_t m_Id;
+    bool m_IdIsSet;
+    int64_t m_PetId;
+    bool m_PetIdIsSet;
+    int32_t m_Quantity;
+    bool m_QuantityIsSet;
+    std::string m_ShipDate;
+    bool m_ShipDateIsSet;
+    std::string m_Status;
+    bool m_StatusIsSet;
+    bool m_Complete;
+    bool m_CompleteIsSet;
+};
+
+}
+}
+}
+}
+
+#endif /* Order_H_ */