sstable add a getter for the sstable stats
sstable add a getter for the sstable stats

This adds a getter function for the statistic of the sstable.

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

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