build(tgbot-gen): Changes and additions required to generate the API client with auth (cookie)

I use a standard set of templates, changes are made in api-header.mustache and api-source.mustache. Their _old versions contain the originals. Additions are necessary for the header argument in the generated functions so that you can authenticate using cookies.

api/_build/my-cpp-templates/cpp-restsdk/apiexception-header.mustache

@@ -0,0 +1,48 @@
+{{>licenseInfo}}
+/*
+ * ApiException.h
+ *
+ * This is the exception being thrown in case the api call was not successful
+ */
+
+#ifndef {{apiHeaderGuardPrefix}}_ApiException_H_
+#define {{apiHeaderGuardPrefix}}_ApiException_H_
+
+{{{defaultInclude}}}
+
+#include <cpprest/details/basic_types.h>
+#include <cpprest/http_msg.h>
+
+#include <memory>
+#include <map>
+
+{{#apiNamespaceDeclarations}}
+namespace {{this}} {
+{{/apiNamespaceDeclarations}}
+
+class {{declspec}} ApiException
+    : public web::http::http_exception
+{
+public:
+    ApiException( int errorCode
+        , const utility::string_t& message
+        , std::shared_ptr<std::istream> content = nullptr );
+    ApiException( int errorCode
+        , const utility::string_t& message
+        , std::map<utility::string_t, utility::string_t>& headers
+        , std::shared_ptr<std::istream> content = nullptr );
+    virtual ~ApiException();
+
+    std::map<utility::string_t, utility::string_t>& getHeaders();
+    std::shared_ptr<std::istream> getContent() const;
+
+protected:
+    std::shared_ptr<std::istream> m_Content;
+    std::map<utility::string_t, utility::string_t> m_Headers;
+};
+
+{{#apiNamespaceDeclarations}}
+}
+{{/apiNamespaceDeclarations}}
+
+#endif /* {{apiHeaderGuardPrefix}}_ApiBase_H_ */