Update lettuce to 3.x

* Update lettuce redis client to latest snapshot, adopt changed API and use API for commands which were emulated using LUA script
* Implement Sentinel support using lettuce library, adopt finer grained exceptions and aligned exception behavior to match other libraries
* Added shutdown-timeout property in order to control shutdown duration of the netty framework which reduces test run duration
* Documentation updated
* Contains also a fix to use psetex instead of setex (typo)
* Switched `MinimumRedisVersionRule` to Jedis since Jedis has a much faster shutdown behavior than lettuce

Reference: DATAREDIS-348
You're thinking about byte[] to String? I'll make sure, there are converters present for both directions (String to byte[] and vice versa)