Update classes to remove Redis name

[jzonthemtn]

Phileas uses Redis for caching in various places - alerts, anonymization, span disambiguation, and policies.

While Phileas does not use Redis itself, these classes have names that include Redis, such as RedisAlertService, and its underlying AbstractRedisCacheService.

Phileas does have a dependency on the redisson client library which is available under the Apache license. Redisson also supports valkey, the Redis fork available under an open source license. AWS is offering valkey as a managed service.

The class naming with respect to Redis should be made generic to not imply that Redis is required for Phileas, when valkey is also an option.

[jzonthemtn]

The bigger idea here is that the cache should not have to be Redis (or Valkey). The abstract cache service should allow for a lot of implementations. Having the abstract class service named AbstractRedisCacheService is very restricting.

I don't like that the AbstractRedisCacheService strongly implies a dependency on Redis.