Don't propagate named loggers.

[JoeZiminski]

This PR sets propagate=False to any created name logger. Due to the insane way that python's logging module works it means that messages are printed to stdout even if log_to_console=False.

This is because, as I understand it, all named loggers are created with root as their 'parent'. By default all child logger messages are propagated to their parent handlers. Therefore if the root logger is used, a StreamHandler is set on it and then the named logger starts logging to console. For example a MRE:

import logging

OUTPUT_FILEPATH = r"C:\Users\Joe\test_log1.log"

fh = logging.FileHandler(OUTPUT_FILEPATH, encoding="utf-8")
fh.setLevel("DEBUG")

logger = logging.getLogger("my_logger")
logger.setLevel("DEBUG")

logger.info("hello world 1")  # does not print to console as expected

# This seems to initialise a StreamHandler on the root
# logger, to which all child loggers are propagated to.
logging.info("log something on root")

logger.info("hello world 2")  # this is now printed to console

The tests are currently failing due to an issue with handlers that will be addressed in #33.

[JoeZiminski]

Rebased onto main and tests passing now, ready for review @adamltyson