[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/Pet.h

@@ -0,0 +1,112 @@
+/**
+* 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.
+*/
+/*
+ * Pet.h
+ *
+ * A pet for sale in the pet store
+ */
+
+#ifndef Pet_H_
+#define Pet_H_
+
+
+#include "ModelBase.h"
+
+#include "Tag.h"
+#include <string>
+#include "Category.h"
+#include <vector>
+
+namespace org {
+namespace openapitools {
+namespace server {
+namespace model {
+
+/// <summary>
+/// A pet for sale in the pet store
+/// </summary>
+class  Pet
+    : public ModelBase
+{
+public:
+    Pet();
+    virtual ~Pet();
+
+    /////////////////////////////////////////////
+    /// ModelBase overrides
+
+    void validate() override;
+
+    nlohmann::json toJson() const override;
+    void fromJson(nlohmann::json& json) override;
+
+    /////////////////////////////////////////////
+    /// Pet members
+
+    /// <summary>
+    /// 
+    /// </summary>
+    int64_t getId() const;
+    void setId(int64_t value);
+    bool idIsSet() const;
+    void unsetId();
+    /// <summary>
+    /// 
+    /// </summary>
+    std::shared_ptr<Category> getCategory() const;
+    void setCategory(std::shared_ptr<Category> value);
+    bool categoryIsSet() const;
+    void unsetCategory();
+    /// <summary>
+    /// 
+    /// </summary>
+    std::string getName() const;
+    void setName(std::string value);
+        /// <summary>
+    /// 
+    /// </summary>
+    std::vector<std::string>& getPhotoUrls();
+        /// <summary>
+    /// 
+    /// </summary>
+    std::vector<std::shared_ptr<Tag>>& getTags();
+    bool tagsIsSet() const;
+    void unsetTags();
+    /// <summary>
+    /// pet status in the store
+    /// </summary>
+    std::string getStatus() const;
+    void setStatus(std::string value);
+    bool statusIsSet() const;
+    void unsetStatus();
+
+protected:
+    int64_t m_Id;
+    bool m_IdIsSet;
+    std::shared_ptr<Category> m_Category;
+    bool m_CategoryIsSet;
+    std::string m_Name;
+
+    std::vector<std::string> m_PhotoUrls;
+
+    std::vector<std::shared_ptr<Tag>> m_Tags;
+    bool m_TagsIsSet;
+    std::string m_Status;
+    bool m_StatusIsSet;
+};
+
+}
+}
+}
+}
+
+#endif /* Pet_H_ */