Support Lettuce connection pooling

[ikovalyov]

Feature description

Lettuce supports connection pooling. We would like to have this functionality in the micronaut-redis. Switching from micronaut's RedisCache to manual queries with connection pool demonstrated improved performance.

[ikovalyov]

#217 @graemerocher

[rjaros87]

Any update on this one? It would be nice to have connection pool for manual queries to Redis.