Enhance /dsmetadata API with cluster name and namespace filtering

[shreyabiradar07]

This PR has following changes -

• Includes cluster and namespace level filtering to retrieve metadata from DB, supporting cluster_name, namespace and verbose input query parameters to /dsmetadata API
• Update existing PromQL queries to incorporate filters by namespace, container, and pod

updated queries -

• NAMESPACE_QUERY -

sum by (namespace) (kube_namespace_status_phase{phase=\"Active\", namespace!='', namespace!~'|openshift|openshift-.*'})

• WORKLOAD_INFO_QUERY -

sum by (namespace, workload, workload_type) (namespace_workload_pod:kube_pod_owner:relabel{container!=' ',container!='POD', pod!=' ', namespace!='', namespace!~'|openshift|openshift-.*'})

• CONTAINER_INFO_QUERY -

sum by (container, image, workload) (kube_pod_container_info on(pod) group_left(workload, workload_type) (namespace_workload_pod:kube_pod_owner:relabel{container!=' ',container!='POD', pod!=' ', namespace!='', namespace!~'|openshift|openshift-.'}))