Reworked headlessCreateUser command in Cypress

[bsekachev]

Motivation and context

Now the command does not set any cookies to the browser automatically.
So, we do not have to use clearCookies() each time after calling cy.headlessCreateUser()

How has this been tested?

Checklist

• I submit my changes into the develop branch
• I have created a changelog fragment
• I have updated the documentation accordingly
• I have added tests to cover my changes
• I have linked related issues (see GitHub docs)

License

• I submit my code changes under the same MIT License that covers the project.
  Feel free to contact the maintainers if that's a concern.

[sonarqubecloud]

Quality Gate failed

Failed conditions
19.6% Duplication on New Code (required ≤ 3%)

See analysis details on SonarQube Cloud

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.83%. Comparing base (4c5e522) to head (a1c9e55).
Report is 1 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #8977   +/-   ##
========================================
  Coverage    73.82%   73.83%           
========================================
  Files          417      417           
  Lines        44591    44591           
  Branches      4031     4031           
========================================
+ Hits         32921    32925    +4     
+ Misses       11670    11666    -4     

Components	Coverage Δ
cvat-ui	78.27% <ø> (+0.01%)	⬆️
cvat-server	70.06% <ø> (ø)