Provide KUD-testing CI visibility at gerrit review level

Currently, there is one job: https://jenkins.onap.org/view/01-Recent/job/multicloud-k8s-kud-deployment-master-shell-6hrs, that is responsible for setting up KUD periodically to ensure it's configuration is valid. This job is not visible though, as it doesn't tests gerrit reviews.

Scope of this task would be to:

• Attach aforementioned job to gerrit reviews via custom label with non-blocking score, so that this job's "-1" won't block merging and "+1" will not be necessary for merge
• Set up CI job to install all KUD addons (currently only default - half of all available) as well as k8splugin. It should run tests for addons and k8splugin