Add possibility to pass JsonSerializerSettings into RedisJSONSerializer

[MaKCbIMKo]

It would be great to have a possibility to pass custom JsonSerializerSettings. Sometimes it requires to modify default reference loop handling (or preserve references handling) for serialization(deserialization). For now, there are two ways:

1. apply this settings globally
2. create a new IRedisSerializer implementation which will be pretty the same, but with only one different thing - possibility to pass custom JsonSerializerSettings.