feat: Add changes to allow redis-watcher to work with flask authz + redis 5

[favipcj]

Fix: #2

This PR covers changes that are needed when using flask-authz, specifically:

1. Add should_reload and update_callback methods that flask-authz needs https://github.com/pycasbin/flask-authz/blob/master/flask_authz/casbin_enforcer.py#L66-L67
2. Retry when Redis times out or when Redis is down for some time
3. Be able to recreate threads after some time(10sec) that were killed for any reason for example when the redis connection dies even after the configured retries. (This is important when running this watcher + flask-authz)
4. Add some error handling to the subscribe method to show message errors related to redis and close the redis connection before the thread is killed
5. Be able to receive a logger instance as an argument when creating the watcher

To make this library work with any Python library Redis version including redis 5, a different instance of the Redis class was created for the subscriber and publisher, as that is required for Redis 5 and still works for other old versions as well.

CI/Unit test Running https://github.com/favipcj/redis-watcher-official/actions/runs/14891376002/job/41824001358

[favipcj]

FYI @hsluoyz

[hsluoyz]

@favipcj plz fix CI error: https://github.com/officialpycasbin/redis-watcher/actions/runs/14909021191/job/41878450101