Allow installation of STF into environments that are not fully connected, such as a proxied network environment.

In a proxy networking environment, a specific set of allowed endpoints must be provided in order to allow the OCP deployment to have access to the endpoints that will provide the deployment artifacts, such as container images and bundle images.

This RFE covers the situation where the OCP deployment is partially connected through a proxy and can retrieve artifacts when supplied with the appropriate allow list of endpoints. For a fully disconnected environment, see RFE at https://bugzilla.redhat.com/show_bug.cgi?id=1885557.