sstables: Make mutation_reader::impl unmovable and uncopyable
sstables: Make mutation_reader::impl unmovable and uncopyable

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