don't load full quiz submissions into memory just to get user ids
don't load full quiz submissions into memory just to get user ids

Change-Id: I29cf331a2a857450622aa6549be89e3edcda7f41
Reviewed-on: https://gerrit.instructure.com/15955
Reviewed-by: Brian Palmer <3cb4e1df5ec4da2c7c4af7c52cec8cf340a55a10@instructure.com>
QA-Review: Brian Palmer <3cb4e1df5ec4da2c7c4af7c52cec8cf340a55a10@instructure.com>
Tested-by: Brian Palmer <3cb4e1df5ec4da2c7c4af7c52cec8cf340a55a10@instructure.com>

Rvor/canvas-lms,narigone/canvas,snehakachroo1/LSI_replica,narigone/canvas,sli7246/canvas_branch,usmschuck/canvas,tgroshon/canvas-lms,matematikk-mooc/canvas-lms,wrdsb/canvas-lms,redconfetti/canvas-lms,arrivu/arrivu-lms,matematikk-mooc/canvas-lms,Jyaasa/canvas-lms,grahamb/canvas-lms,skmezanul/canvas-lms,instructure/canvas-lms,redconfetti/canvas-lms,antoniuslin/canvas-lms,Unow/ins,utkarshx/canvas-lms,arrivu/jigsaw-lms,samuels410/greatlakes-lms,wye0220/shindig-canvas,arrivu/jigsaw-lms,nditech/red-innovadores-lms,shidao-fm/canvas-lms,arrivu/hiring-site,roxolan/canvas-lms,eCNAP/CANVAS,roxolan/canvas-lms,dgynn/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,antoniuslin/canvas-lms,greyhwndz/canvas-lms,Unow/canvas-lms,SwinburneOnline/canvas-lms,leftplusrightllc/canvas-lms,wye0220/shindig-canvas,sfu/canvas-lms,Unow/ins,instructure/canvas-lms,wrdsb/canvas-lms,Rvor/canvas-lms,djbender/canvas-lms,antoniuslin/canvas-lms,SwinburneOnline/canvas-lms,ShreniiNepal/shrenii_lmp,djbender/canvas-lms,merichar/canvas-lms,kyroskoh/canvas-lms,juoni/canvas-lms,arrivu/hoodemo,ShreniiNepal/shrenii_lmp,antoniuslin/canvas-lms,HotChalk/canvas-lms,kyroskoh/canvas-lms,nditech/red-innovadores-lms,Jyaasa/canvas-lms,ShreniiNepal/shrenii_lmp,leftplusrightllc/canvas-lms,va7map/canvas-lms,eCNAP/CANVAS,ShreniiNepal/shrenii_lmp,jay3126/canvas-lms,loganrun/pincan,sdeleon28/canvas-lms,whalejasmine/canvas-lms,shidao-fm/canvas-lms,instructure/canvas-lms,sdeleon28/canvas-lms,utkarshx/canvas-lms,arrivu/hoodemo,sfu/canvas-lms,snehakachroo1/LSI_replica,rup/Tarrax,sfu/canvas-lms,efrj/canvas-lms,sfu/canvas-lms,fronteerio/canvas-lms,greyhwndz/canvas-lms,Jyaasa/canvas-lms,AndranikMarkosyan/lms,greyhwndz/canvas-lms,grahamb/canvas-lms,gbleydon/canvas-lms,wimemx/Canvas,skmezanul/canvas-lms,samuels410/greatlakes-lms,loganrun/pincan,wye0220/shindig-canvas,skmezanul/canvas-lms,arrivu/qibla-ecampus,fronteerio/canvas-lms,arrivu/hiring-site,efrj/canvas-lms,rup/Tarrax,AndranikMarkosyan/lms,narigone/canvas,parbros/red-innovadores-lms,skmezanul/canvas-lms,landonwilkins/canvas-lms,narigone/canvas,parbros/red-innovadores-lms,HotChalk/canvas-lms,va7map/canvas-lms,wimemx/Canvas,kyroskoh/canvas-lms,grahamb/canvas-lms,AndranikMarkosyan/lms,grahamb/canvas-lms,dgynn/canvas-lms,sfu/canvas-lms,rup/Tarrax,redconfetti/canvas-lms,shidao-fm/canvas-lms,usmschuck/canvas,tgroshon/canvas-lms,dgynn/canvas-lms,landonwilkins/canvas-lms,venturehive/canvas-lms,samuels410/greatlakes-lms,fronteerio/canvas-lms,SwinburneOnline/canvas-lms,Unow/canvas-lms,jay3126/canvas-lms,merichar/canvas-lms,landonwilkins/canvas-lms,samuels410/greatlakes-lms,wrdsb/canvas-lms,kyroskoh/canvas-lms,arrivu/qibla-ecampus,venturehive/canvas-lms,loganrun/pincan,sdeleon28/canvas-lms,efrj/canvas-lms,Unow/ins,HotChalk/canvas-lms,arrivu/qibla-ecampus,utkarshx/canvas-lms,sli7246/canvas_branch,arrivu/arrivu-lms,utkarshx/canvas-lms,gbleydon/canvas-lms,whalejasmine/canvas-lms,parbros/red-innovadores-lms,roxolan/canvas-lms,juoni/canvas-lms,snehakachroo1/LSI_replica,grahamb/canvas-lms,matematikk-mooc/canvas-lms,fronteerio/canvas-lms,arrivu/arrivu-lms,djbender/canvas-lms,HotChalk/canvas-lms,Rvor/canvas-lms,leftplusrightllc/canvas-lms,nditech/red-innovadores-lms,instructure/canvas-lms,shidao-fm/canvas-lms,roxolan/canvas-lms,sli7246/canvas_branch,Rvor/canvas-lms,merichar/canvas-lms,nditech/red-innovadores-lms,leftplusrightllc/canvas-lms,matematikk-mooc/canvas-lms,juoni/canvas-lms,juoni/canvas-lms,arrivu/jigsaw-lms,djbender/canvas-lms,va7map/canvas-lms,greyhwndz/canvas-lms,AndranikMarkosyan/lms,instructure/canvas-lms,eCNAP/CANVAS,sdeleon28/canvas-lms,arrivu/hiring-site,jay3126/canvas-lms,redconfetti/canvas-lms,landonwilkins/canvas-lms,whalejasmine/canvas-lms,va7map/canvas-lms,tgroshon/canvas-lms,Unow/canvas-lms,eCNAP/CANVAS,snehakachroo1/LSI_replica,wimemx/Canvas,SwinburneOnline/canvas-lms,dgynn/canvas-lms,venturehive/canvas-lms,jay3126/canvas-lms,instructure/canvas-lms,usmschuck/canvas,whalejasmine/canvas-lms,efrj/canvas-lms,wrdsb/canvas-lms,arrivu/hoodemo,Jyaasa/canvas-lms,gbleydon/canvas-lms,tgroshon/canvas-lms,usmschuck/canvas,venturehive/canvas-lms,sfu/canvas-lms