Clang format

[2bndy5]

As promised:

• replace old AStyle config with Arduino (IDE v2.0) clang-format config for the examples' src code.
• add a clang-format config for the lib src code.
• change workflows to use clang-format to check formatting.
  • All sources that were copied from UIP stack lib are ignored by clang-format in the CI workflows. This should make it easier to make updates when needed from the original sources (even though it isn't maintained anymore - they migrated to a 2.0 revised repo).
• Updated CI to use Doxygen v1.9.4 (only for consistency with the other nRF24 repos -- its not really needed since we're not building sphinx docs from the Doxygen XML for this lib).

Notes

Nothing I noticed in the diff is worthy of concern here. This went rather smoothly.

[github-actions]

Memory usage change @ a4d4834

Board	flash	%	RAM for global variables	%
arduino:avr:nano	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrzero	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0

Click for full report table

Board	examples/Getting_Started_SimpleClient_Mesh flash	%	examples/Getting_Started_SimpleClient_Mesh RAM for global variables	%	examples/Getting_Started_SimpleServer_Mesh flash	%	examples/Getting_Started_SimpleServer_Mesh RAM for global variables	%	examples/InteractiveServer_Mesh flash	%	examples/InteractiveServer_Mesh RAM for global variables	%	examples/MQTT/mqtt_basic flash	%	examples/MQTT/mqtt_basic RAM for global variables	%	examples/MQTT/mqtt_basic_2 flash	%	examples/MQTT/mqtt_basic_2 RAM for global variables	%	examples/SimpleClient_Mesh flash	%	examples/SimpleClient_Mesh RAM for global variables	%
arduino:avr:nano	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0
arduino:samd:mkrzero	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0

Click for full report CSV

Board,examples/Getting_Started_SimpleClient_Mesh<br>flash,%,examples/Getting_Started_SimpleClient_Mesh<br>RAM for global variables,%,examples/Getting_Started_SimpleServer_Mesh<br>flash,%,examples/Getting_Started_SimpleServer_Mesh<br>RAM for global variables,%,examples/InteractiveServer_Mesh<br>flash,%,examples/InteractiveServer_Mesh<br>RAM for global variables,%,examples/MQTT/mqtt_basic<br>flash,%,examples/MQTT/mqtt_basic<br>RAM for global variables,%,examples/MQTT/mqtt_basic_2<br>flash,%,examples/MQTT/mqtt_basic_2<br>RAM for global variables,%,examples/SimpleClient_Mesh<br>flash,%,examples/SimpleClient_Mesh<br>RAM for global variables,%
arduino:avr:nano,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0
arduino:samd:mkrzero,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0