Merge branch 'andrey-add-custom-metrics' into 'master'

Add ability to add additional custom test metrics

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/105151



Merged-by: Mark Lapierre <mlapierre@gitlab.com>
Approved-by: Mark Lapierre <mlapierre@gitlab.com>
Co-authored-by: Andrejs Cunskis <acunskis@gitlab.com>