[C++][RestSDK] Windows vcpkg vs2017 support (#2751)

* Add boost-uid to vcpkg isntall command. It's required.

* Add instructions for building on visual studio 2017

* Add section to support vcpkg and visual studio

* Undef U on windows to stop compiler error

* Update pet store sample

* Move undef U to apiclient-header

* Slight change to address compiler warning

samples/client/petstore/cpp-restsdk/api/PetApi.h

@@ -27,6 +27,10 @@
 #include <cpprest/details/basic_types.h>
 
 
+#ifdef _WIN32 | _WIN64
+#undef U
+#endif
+
 #include <boost/optional.hpp>
 
 namespace org {

samples/client/petstore/cpp-restsdk/api/StoreApi.h

@@ -26,6 +26,10 @@
 #include <cpprest/details/basic_types.h>
 
 
+#ifdef _WIN32 | _WIN64
+#undef U
+#endif
+
 #include <boost/optional.hpp>
 
 namespace org {

samples/client/petstore/cpp-restsdk/api/UserApi.h

@@ -26,6 +26,10 @@
 #include <cpprest/details/basic_types.h>
 
 
+#ifdef _WIN32 | _WIN64
+#undef U
+#endif
+
 #include <boost/optional.hpp>
 
 namespace org {