logging: bypass esp_log output

[SpComb]

Keep using the esp_log formatting for our own LOG_* macros, but skip the tag/level mechanisms and just output directly on stderr.

This means we can use build-time #define DEBUG for debug-level logging at the *.c file level without having to raise the CONFIG_LOG_DEFAULT_LEVEL and including all debug logging into the firmware. Skip the esp_log tag/level mechanism because we don't use it for setting runtime log levels.