Example request: A working ESP32WebMenu example would be nice

[ScruffR]

I tried to convert the esp8266_WebMenu example to support ESP32, however the sample does not build due to several errors

• there is an #include "user_interface.h" but no such file exists
• streamFlow.h is required but not available in Arduino Library Manager (manually copied though)
• (after manually copying streamFlow) endl and endlObj are used but undefined
• (after defining these two) several objects in (an adapted) esp8266Out.hpp were not defined
• ...