Fix cluster API load balancer lookup in the cleanup script
Created by: matofeder
The cleanup script did not consider a cluster name when it looked for load balancers created by CAPI. This might cause the cleanup script wrongly removes all CAPI load balancers from the OpenStack project, when e.g. two CAPI clusters (with different names) want to share one OpenStack project.
This PR adds a cluster name to the filter of CAPI load balancers.
Closes #344 (closed)