API: Add row related method to cache_service API
API: Add row related method to cache_service API

This adds the implementation for get_row_hits, get_row_requests,
get_row_hit_rate, row_enries, row_size and row_capacity

The implementation is based on the column-family map reduce

Signed-off-by: Amnon Heiman <ed5fc74c4692051ad0b19749fd7cea6ec2d74b9e@cloudius-systems.com>

aruanruan/scylla,justintung/scylla,respu/scylla,duarten/scylla,stamhe/scylla,linearregression/scylla,kangkot/scylla,glommer/scylla,bowlofstew/scylla,stamhe/scylla,duarten/scylla,rentongzhang/scylla,glommer/scylla,aruanruan/scylla,linearregression/scylla,stamhe/scylla,asias/scylla,capturePointer/scylla,kangkot/scylla,avikivity/scylla,duarten/scylla,victorbriz/scylla,phonkee/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,bowlofstew/scylla,justintung/scylla,rentongzhang/scylla,guiquanz/scylla,raphaelsc/scylla,wildinto/scylla,phonkee/scylla,asias/scylla,kjniemi/scylla,phonkee/scylla,raphaelsc/scylla,rluta/scylla,kangkot/scylla,tempbottle/scylla,capturePointer/scylla,rluta/scylla,kjniemi/scylla,dwdm/scylla,eklitzke/scylla,guiquanz/scylla,wildinto/scylla,gwicke/scylla,justintung/scylla,linearregression/scylla,kjniemi/scylla,tempbottle/scylla,guiquanz/scylla,acbellini/scylla,raphaelsc/scylla,shaunstanislaus/scylla,dwdm/scylla,tempbottle/scylla,respu/scylla,eklitzke/scylla,respu/scylla,acbellini/scylla,gwicke/scylla,senseb/scylla,bowlofstew/scylla,aruanruan/scylla,shaunstanislaus/scylla,dwdm/scylla,senseb/scylla,rentongzhang/scylla,glommer/scylla,shaunstanislaus/scylla,victorbriz/scylla,acbellini/scylla,eklitzke/scylla,capturePointer/scylla,gwicke/scylla,asias/scylla,senseb/scylla,avikivity/scylla,rluta/scylla,scylladb/scylla,wildinto/scylla,victorbriz/scylla