ESP32 support + example fix (AVR DebugUtils removal)

[ubidefeo]

This PR adds ConnectionHandler support for ESP32-based boards and fixes the demo example which was still calling setDebugLevel() although that was not enabled for MegaAVR

[per1234]

@ubidefeo please let me know if you want me to assist with an update of the CI workflow to also compile the examples for ESP32.

[github-actions]

Memory usage change @ 61e3a2a

Board	flash	%	RAM for global variables	%
arduino:mbed:envie_m4	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:mbed:envie_m7	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkr1000	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrgsm1400	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrnb1500	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrwan1300	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrwan1310	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrwifi1010	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:nano_33_iot	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
esp8266:esp8266:huzzah	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0

Click for full report table

Board	examples/ConnectionHandlerDemo flash	%	examples/ConnectionHandlerDemo RAM for global variables	%
arduino:mbed:envie_m4	0	0.0	0	0.0
arduino:mbed:envie_m7	0	0.0	0	0.0
arduino:samd:mkr1000	0	0.0	0	0.0
arduino:samd:mkrgsm1400	0	0.0	0	0.0
arduino:samd:mkrnb1500	0	0.0	0	0.0
arduino:samd:mkrwan1300	0	0.0	0	0.0
arduino:samd:mkrwan1310	0	0.0	0	0.0
arduino:samd:mkrwifi1010	0	0.0	0	0.0
arduino:samd:nano_33_iot	0	0.0	0	0.0
esp8266:esp8266:huzzah	0	0.0	0	0.0

Click for full report CSV

Board,examples/ConnectionHandlerDemo<br>flash,%,examples/ConnectionHandlerDemo<br>RAM for global variables,%
arduino:mbed:envie_m4,0,0.0,0,0.0
arduino:mbed:envie_m7,0,0.0,0,0.0
arduino:samd:mkr1000,0,0.0,0,0.0
arduino:samd:mkrgsm1400,0,0.0,0,0.0
arduino:samd:mkrnb1500,0,0.0,0,0.0
arduino:samd:mkrwan1300,0,0.0,0,0.0
arduino:samd:mkrwan1310,0,0.0,0,0.0
arduino:samd:mkrwifi1010,0,0.0,0,0.0
arduino:samd:nano_33_iot,0,0.0,0,0.0
esp8266:esp8266:huzzah,0,0.0,0,0.0

[aentinger]

LGTM 👍 Thank you @ubidefeo 🚀

[aentinger]

@per1234 ESP32 CI support would be fantastic! I've created #48 and assigned it to you to keep track of it.

[ubidefeo]

@aentinger my previous attempt got totally messed up by SublimeText deciding to change all my whitespace and add newlines (I have some pretty messed up settings RN).
Ended up making the changes in VS Code and it all went well.

@per1234 please do! 🙏🏼

[ubidefeo]

@aentinger should I merge this on?
I guess with admin rights on the repo the flow is
PULL REQ me
REVIEW you
MERGE me

I also think that on release of this one IoTCloud should also be re-released, as I remember some changes being in there as well but not sure they've been released yet

[aentinger]

Please go ahead and merge this one. I'd like to first have CI running for ESP32 both here (#48) and on ArduinoIoTCloud (arduino-libraries/ArduinoIoTCloud#215) before a new library is officially released.