feat: add exports for log format functions

- Add `log_default_logger` to get a default logger.
- Add exports for `log_set_format`, `log_set_level` and `log_default_logger` functions.
- Add `current_cord_name` function to get a name of the current cord,
- add `cord_is_main_dont_create` function.
- Add exports for `cord_is_main`, `cord_is_main_dont_create` and
- `current_cord_name` functions.

NO_DOC=internal
NO_TEST=internal
NO_CHANGELOG=internal