add low level 2d profile plot function and 2d profile function#1652

EchoRLiu wants to merge 7 commits intodevelopICB-DCM/pyPESTO:developfrom

1651-profiles-do-not-show-if-dropoff-due-to-bound-hittingICB-DCM/pyPESTO:1651-profiles-do-not-show-if-dropoff-due-to-bound-hittingCopy head branch name to clipboard