Feature 10509 manual scaling for native K8s charm

This robot test created for this specific package
vnf-onboarding/osm-packages!154


Test case steps:
1 - Adds packages
2 - Adds K8s Cluster
3 - Creates NS Service
4 - Gets the scale count
5 - Scale-out the NS
6 - Checks scale count
7 - Scale-in the NS
8 - Check scale count
9 - Removes the NS, K8s cluster and packages
This commit includes Juju support

Change-Id: Iba7c59a65c9ae2607b23c7104e8178e20b502c60
Signed-off-by: aktas <emin.aktas@ulakhaberlesme.com.tr>
(cherry picked from commit f47542be)