Migrate `RedisConnectionFactory` to `Lifecycle` beans

[mp911de]

Based on spring-projects/spring-framework#29921, we could move our connection factories towards beans that implement the lifecycle. This would be especially useful to decouple afterPropertiesSet from the connection pool startup and dispose() where we dispose resources. With start() and stop() connection factories could start up pools and tear down as necessary without destroying the entire bean.

[jxblum]

@mp911de - I'd need to think on this a bit more, but my first reaction when I read your comment is that this might also (would) be beneficial when using Spring Data Redis with CRaC (on GitHub) in conjunction with Spring Framework's (eventual/very-likely) support thereof.