Default PROJ debug level

[snowman2]

With #2527, errors are no longer raised by default.

This is because PJ_LOG_NONE is the default:

• PROJ/src/ctx.cpp

  Line 90 in cd10468

  ctx.debug_level = PJ_LOG_NONE;

• PROJ/src/proj_internal.h

  Line 650 in cd10468

  int debug_level = 0;

Thoughts about making the default level PJ_LOG_ERROR so errors are logged by default?

[snowman2]

https://docs.python.org/3/howto/logging.html
"The root logger always has an explicit level set (WARNING by default)"

Seems like having ERROR as the default is reasonable if you follow the python logging pattern. Any opposition?