tests/cql3: test setting collections to null
tests/cql3: test setting collections to null

Signed-off-by: Paweł Dziepak <e29bb3265626c60caf76d587cabdfcd8b379ef80@cloudius-systems.com>

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