[BUG]: The load list commands increase memory footprint indefinetely.

[slice4e]

The load list commands:
memtier_benchmark-1Mkeys-load-list-with-1KiB-values
memtier_benchmark-1Mkeys-load-list-with-100B-values
memtier_benchmark-1Mkeys-load-list-with-10B-values

keep growing in memory capacity. If multiple memtier runs are specified, this would result in consuming more memory than specified.

[filipecosta90]

Ideally we should move away from memtier and use a specific tool or ingesting this type of datatypes that keep growing indefinitely ( like we have in https://github.com/redis-performance/redis-zbench-go for sorted sets )