refactor(utils): make logger decoupled from dsn runtime

[levy5307]

The logger API, is tightly coupled in rdsn runtime for historical issues. As a part of the long-term plan of rdsn (see #141 ) we decoupled it to make further refactoring possible.

[neverchanje]

If the config file is not loaded by dsn_runtime, we can get nothing from it

dsn_runtime depends on config-lib, you misunderstood that config-lib depends on dsn_runtime. Every application can use dsn_config_load to read config, it's not limited to dsn_runtime only.

    if (!dsn_config_load(config_file, config_arguments)) {
        printf("Fail to load config file %s\n", config_file);
        return false;
    }

So logger depends on config-lib is reasonable.
We can first decouple logger from dsn_runtime, then in PR afterward we can decouple logger with config-lib, if it's worthwhile.