Fix group display name logic

[floreks]

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #2803

Release note:

Fix missing group name on Service Account list.

[kubermatic-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: floreks

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[codecov]

Codecov Report

Merging #2851 (cb43532) into master (54f37b7) will increase coverage by 0.11%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2851      +/-   ##
==========================================
+ Coverage   52.35%   52.47%   +0.11%     
==========================================
  Files         234      234              
  Lines        8188     8189       +1     
  Branches      939      939              
==========================================
+ Hits         4287     4297      +10     
+ Misses       3898     3890       -8     
+ Partials        3        2       -1     

Impacted Files	Coverage Δ
src/app/shared/utils/member-utils/member-utils.ts	85.29% <100.00%> (+0.44%)	⬆️
src/app/project/project.component.ts	73.16% <0.00%> (+3.89%)	⬆️

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[maciaszczykm]

/lgtm

[kubermatic-bot]

LGTM label has been added.

Git tree hash: fc4cbca56f0e76a0086be296e4a232bea0c7c15a