Add OS_<SERVICE>_API_VERSION=<supported highest api microversion> as envVars for opsntackclient pod.

Currently, there is no definition for services' api version. That means, users must specify the required minimum api version for their operations.
It is really annoying and we should resolve this situation.

As far as I read, the code in openstack-operator has a section to define envVars for openstackclient pod.
https://github.com/openstack-k8s-operators/openstack-operator/blob/main/pkg/openstackclient/funcs.go#L31-L51

This request has a benefit to all users in RHOSO18.