Merge branch 'add-ingress-to-cluster-applications' of gitlab.com:gitlab-org/gitlab-ce into add-ingress-to-cluster-applications

Add applications section to GKE clusters page

See merge request gitlab-org/gitlab-ce!15064

Conflicts:
	app/assets/javascripts/clusters/clusters_bundle.js
	app/assets/javascripts/clusters/components/application_row.vue
	app/assets/javascripts/clusters/services/clusters_service.js

CE repository mirroring changes backport

See merge request gitlab-org/gitlab-ce!15184

Added discussion_line_code value to note response and use it to query the right…

Closes #38677

See merge request gitlab-org/gitlab-ce!14981

Merge remote-tracking branch 'origin/refactor-clusters' into 36629-35958-add-cluster-application-section

Merge remote-tracking branch 'origin/38464-k8s-apps' into 36629-35958-add-cluster-application-section