Merge branch 'ph/517583/mrDashboardLabelsToggle' into 'master'

Added a show labels toggle to the merge request dashboard

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/181395



Merged-by: Kushal Pandya <kushal@gitlab.com>
Approved-by: Michael Le <mle@gitlab.com>
Approved-by: Ankit Panchal <apanchal@gitlab.com>
Approved-by: Kushal Pandya <kushal@gitlab.com>
Reviewed-by: Kushal Pandya <kushal@gitlab.com>
Reviewed-by: Michael Le <mle@gitlab.com>
Reviewed-by: Ankit Panchal <apanchal@gitlab.com>
Reviewed-by: GitLab Duo <gitlab-duo@gitlab.com>
Co-authored-by: Phil Hughes <me@iamphill.com>