EVEREST-107 update IMAGE_TAG_OWNER

[oksana-grishchenko]

Problem:
After the 1.1.0 release it turned out that Everest still installs the everest-operator image from perconalab:

$ kubectl get po -l app.kubernetes.io/name=everest-operator -o yaml -n everest-system | grep image
...
image: docker.io/perconalab/everest-operator:1.1.0

Cause:
There is this make bundle command which is used during the operator release. This command uses
the IMG variable, which uses
the IMAGE_TAG_BASE variable, which uses
the IMAGE_TAG_OWNER variable, which was always set to perconalab
and as a result config/manager/kustomization.yaml is always linked to perconalab

Solution:
Update the Makefile during the release so that depending on the build type (RC or Release) the IMAGE_TAG_OWNER would point to perconalab or percona