Upgrade prometheus-exporter-operator to operator-sdk v1

[slopezz]

There have been many changes on operator-sdk v1, like the manifest bundle format for OLM, it is the moment to upgrade from old operator-sdk v0 (specifically v0.18.1) to a recent v1 version.

[slopezz]

• Created issue regarding bug with multi-namespace installMode support (operator does not notice missing dependant objects from managed CRs that might have been manually deleted, so never recreates them): Ansible operator does not detect unauthorized changes to resources that are managed by the operator on multi namespace mode operator-framework/operator-sdk#4647

• Created issue regarding bug on operator-sdk v1.5.0 with kube-rbac-proxy container permission denied : Ansible operator-sdk v1.5.0 with updated kube-rbac-proxy:v0.8.0 fails to run with permission denied operator-framework/operator-sdk#4684