Log the release of Arduino-ESP32 in the Arduino BLE samples

[nkolban]

The BLE samples for Arduino apparently can run on a variety of releases of Arduino-ESP32. What we want to do is have our samples "log" the version of Arduino-ESP32 that is actually being used.

Actions: Study the Arduino-ESP32 library. If needed, ask mr @me-no-dev if there is a "getVersion()" or macro or some other "at compile time" determination of which version of the Arduino-ESP32 library is present at compile time.