tests: add test for set literals and set addiitions
tests: add test for set literals and set addiitions

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