fix mastery score of 0 not showing up in outcome hover on student lmgb
fix mastery score of 0 not showing up in outcome hover on student lmgb

fixes CNVS-19435

test plan:
- create an outcome (easiest to check this w/ latest score method)
- attach it to an assignment and give a student a mastery score of 0
- go to student lmgb, the outcome's hover should reflect a score of 0

Change-Id: Ic010acdb525276fa4566400ab6e7a5e3f3910735
Reviewed-on: https://gerrit.instructure.com/50729
Tested-by: Jenkins
QA-Review: Deepeeca Soundarrajan <5bcd4b623f00b7fc2942cd1c65c245b30a48a61f@instructure.com>
Reviewed-by: Simon Williams <088e16a1019277b15d58faf0541e11910eb756f6@instructure.com>
Product-Review: Simon Williams <088e16a1019277b15d58faf0541e11910eb756f6@instructure.com>

juoni/canvas-lms,leftplusrightllc/canvas-lms,Jyaasa/canvas-lms,greyhwndz/canvas-lms,va7map/canvas-lms,samuels410/greatlakes-lms,sfu/canvas-lms,roxolan/canvas-lms,skmezanul/canvas-lms,sfu/canvas-lms,kyroskoh/canvas-lms,utkarshx/canvas-lms,djbender/canvas-lms,fronteerio/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,skmezanul/canvas-lms,ShreniiNepal/shrenii_lmp,whalejasmine/canvas-lms,HotChalk/canvas-lms,utkarshx/canvas-lms,sdeleon28/canvas-lms,kyroskoh/canvas-lms,va7map/canvas-lms,antoniuslin/canvas-lms,jay3126/canvas-lms,Rvor/canvas-lms,tgroshon/canvas-lms,juoni/canvas-lms,tgroshon/canvas-lms,kyroskoh/canvas-lms,efrj/canvas-lms,efrj/canvas-lms,venturehive/canvas-lms,venturehive/canvas-lms,grahamb/canvas-lms,shidao-fm/canvas-lms,utkarshx/canvas-lms,sdeleon28/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,shidao-fm/canvas-lms,greyhwndz/canvas-lms,fronteerio/canvas-lms,kyroskoh/canvas-lms,juoni/canvas-lms,tgroshon/canvas-lms,redconfetti/canvas-lms,jay3126/canvas-lms,ShreniiNepal/shrenii_lmp,HotChalk/canvas-lms,redconfetti/canvas-lms,efrj/canvas-lms,leftplusrightllc/canvas-lms,sfu/canvas-lms,utkarshx/canvas-lms,SwinburneOnline/canvas-lms,leftplusrightllc/canvas-lms,redconfetti/canvas-lms,whalejasmine/canvas-lms,juoni/canvas-lms,grahamb/canvas-lms,va7map/canvas-lms,grahamb/canvas-lms,antoniuslin/canvas-lms,samuels410/greatlakes-lms,sfu/canvas-lms,sdeleon28/canvas-lms,jay3126/canvas-lms,samuels410/greatlakes-lms,venturehive/canvas-lms,redconfetti/canvas-lms,roxolan/canvas-lms,SwinburneOnline/canvas-lms,sfu/canvas-lms,whalejasmine/canvas-lms,whalejasmine/canvas-lms,jay3126/canvas-lms,wrdsb/canvas-lms,venturehive/canvas-lms,Rvor/canvas-lms,greyhwndz/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,Rvor/canvas-lms,sdeleon28/canvas-lms,samuels410/greatlakes-lms,efrj/canvas-lms,roxolan/canvas-lms,SwinburneOnline/canvas-lms,leftplusrightllc/canvas-lms,wrdsb/canvas-lms,HotChalk/canvas-lms,shidao-fm/canvas-lms,roxolan/canvas-lms,greyhwndz/canvas-lms,va7map/canvas-lms,wrdsb/canvas-lms,antoniuslin/canvas-lms,HotChalk/canvas-lms,ShreniiNepal/shrenii_lmp,skmezanul/canvas-lms,fronteerio/canvas-lms,Jyaasa/canvas-lms,wrdsb/canvas-lms,Jyaasa/canvas-lms,Jyaasa/canvas-lms,skmezanul/canvas-lms,antoniuslin/canvas-lms,ShreniiNepal/shrenii_lmp,djbender/canvas-lms,shidao-fm/canvas-lms,Rvor/canvas-lms,tgroshon/canvas-lms,fronteerio/canvas-lms,grahamb/canvas-lms