redis: avoid building UniversalOptions for standard mode This makes it support all options that go-redis recognizes in ParseURL, by constructing a standard client directly instead of building UniversalOptions ourselves.
redis: use UniveralClient, support sentinel mode This commit switches the redis client to using a UniversalClient [1], which can operate in standard, cluster, or failover (sentinel) mode. It also implements basic support for having (multiple) `redis+sentinel://` URLs as connection URL in the config (e.g. for `redis-host`). This is the Go equivalent of the proposed Python patch [2]. It supports the same examples given there. [1] https://pkg.go.dev/github.com/go-redis/redis/v8#UniversalClient [2] https://lists.sr.ht/~sircmpwn/sr.ht-dev/patches/55521