custom profile field fixes/enhancements, refs CNVS-4556
custom profile field fixes/enhancements, refs CNVS-4556

1. allow types other than string (currently just int and float)
2. set value to nil if blank

test plan:
N/A, see plugin commits

Change-Id: Ib0ccd77a84467a42dd14d46f3b9216cbcc1e6bf8
Reviewed-on: https://gerrit.instructure.com/18824
Tested-by: Jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@instructure.com>
QA-Review: Cam Theriault <b4133c36b6d893d0872cc09e87b536d16aa2d241@instructure.com>
Reviewed-by: Joe Tanner <16a9a54ddf4259952e3c118c763138e83693d7fd@instructure.com>
Product-Review: Jon Jensen <44f878afe53efc66b76772bd845eb65944ed8232@instructure.com>

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