[ENHANCEMENT] Appropriate behavior when redis is down

[vicilliar]

Describe the solution you'd like When throttling is enabled and marqo tries to connect to redis while redis is down, a warning is logged. It should also do 1 or both of these things:

1. Attempt to restart redis through something like subprocess.run("redis-server /etc/redis/redis.conf", shell=True)
2. Indicate in the healthcheck somehow that redis is down. We could have some new status to indicate this.