Quay setup behind a Proxy

Story: As a Quay administrator I may deploy Quay on an OpenShift cluster in a proxied environments. I expect the Operator to allow to configure Quay for that specific proxy so that I can use repo mirroring with upstream repositories through that proxy.

Acceptance criteria:

• OCP cluster-wide proxy config propagated by OLM onto the Quay Operator pod via environment variables should be propagated down to Quay and Repo Mirroring pods
• the Operator should allow to overwrite the Quay proxy settings individually, thus overwriting a potentially configured OCP cluster-wide proxy
• proxy configuration can either be expressed in the Quay config bundle or via environment variables