Ignore build file warnings for Arduino; Update examples

[gojimmypi]

Description

Defines WOLFSSL_IGNORE_FILE_WARN for the Arduino platform to ignore compile-time warnings in Arduino due to build system limitations noted in wolfSSL/Arduino-wolfSSL#1 with a root cause described in arduino/arduino-cli#631.

Both the wolfcrypt default settings.h and example Arduino user_settings.h file have been updated.

This is a nice-to-have, but not essential update to hopefully make it into the upcoming release.

Without this update, there are warnings such as this one observed in the PlatformIO Arduino build:

.pio/libdeps/esp32dev/wolfssl/src/wolfcrypt/src/bio.c:35:10: warning: #warning bio.c does not need to be compiled separately from ssl.c [-Wcpp]
         #warning bio.c does not need to be compiled separately from ssl.c
          ^~~~~~~

The Arduino warnings (and in fact the entire log) is hidden unless otherwise turned enabled for the Arduino IDE. PlatformIO is the opposite: showing the entire compiler log by default.

• edit: I needed to refresh/rebase from upstream, so I took the opportunity to also polish existing Arduino examples as well as add a new, bare-bones wolfssl_version.ino example.

Fixes zd# n/a

Fixes #7330

Testing

How did you test?

Tested in Arduino only.

Checklist

• added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation