Implement esp_log_level_get(TAG) (IDFGH-4770)

[0xFEEDC0DE64]

Add simple getter for current log level to skip expensive log construction.

example usage:

#include <string>
#include <esp_log.h>

extern std::string slowLogBuilder();

namespace {
constexpr const char TAG[] = "MAIN";
}

void someMethod()
{
    if (esp_log_level_get(TAG) >= ESP_LOG_DEBUG)
        ESP_LOGD(TAG, "current log status=%s", slowLogBuilder().c_str());
}
}

[Alvin1Zhang]

Thanks for your contribution.

[0xFEEDC0DE64]

Ok is this PR already in consideration? Are any questions open? Can I help somehow to get this merged?

[0xFEEDC0DE64]

Ping?