Change SERIAL_DEBUG into RF24_DEBUG

[2bndy5]

Basically, we need a way to differentiate between enabling RF24 debug output and enabling RF24Network debug output when compiling the RF24 stack into a single binary. This probably isn't a big concern, but the RF24 debug output can be noisy and make it difficult to see/find debug output from RF24Network.

Describe the solution you'd like
Just as the title says: Change SERIAL_DEBUG into RF24_DEBUG. We should also update the macro name from IF_SERIAL_DEBUG() into IF_RF24_DEBUG(). Doing this will avoid having to change the toggle/flags for the various levels of debug output in RF24Network.

Describe alternatives you've considered
None

Additional context
See nRF24/pyRF24#64 (comment). While this problem was identified in the pyRF24 project, I think it would also affect any project that involves RF24 and RF24Network libs using debug output for the Arduino and PicoSDK platforms. This problem is not present in typical usage on Linux where the RF24 stack is compiled into separate binary drivers.

[2bndy5]

In researching why some portability uses

RF24/utility/ATXMegaD3/RF24_arch_config.h

Line 33 in 29231f2

#undef SERIAL_DEBUG

I found a comment way back in 2016 that might be trying to reference this situation. 😄

[TMRh20]

Hehe, I think the RF24Network define should probably be changed to RF24NETWORK_DEBUG too.

[2bndy5]

Yeah, we can do that too. It is just a simple search and replace solution.

[2bndy5]

BTW, the debug toggle in RF24Mesh is MESH_DEBUG. Do you want to prefix that to be RF24MESH_DEBUG?

[TMRh20]

Sure - Nice and consistent and very unlikely to be repeated in other code.

[2bndy5]

RF24Ethernet seems to be already using some lib-specific debug toggle names.

RF24Gateway seems to use a DEBUG_LEVEL in which the integer value dictates the verbosity of debug output. I'm guessing DEBUG_LEVEL should probably get renamed to RF24GATEWAY_DEBUG_LEVEL as well?

[TMRh20]

Yeah lol