(ci) Add coverage integration into GitLab (#447)

Add coverage keyword and regex
Before GitLab v15.0, it used to be into the project settings
now, it’s into the CI config
This fixes previously working feature
https://docs.gitlab.com/ee/ci/pipelines/settings.html#merge-request-test-coverage-results

Add xml coverage report
base on that GitLab coverage integration
https://docs.gitlab.com/ee/ci/testing/test_coverage_visualization.html#python-example