Remove console plugin from operator config on operator uninstall

Related to CONSOLE-2380

We need a way for cluster admins to disable a console plugin when uninstalling an operator if it's enabled in the console operator config. Otherwise, the config will reference a plugin that no longer exists. This won't prevent console from loading, but it's something that we can clean up during uninstall.

The UI will always remove the console plugin when an operator is uninstalled. There will not be an option to keep the operator. We should have a sentence in the dialog letting the user know that the plugin will disabled when the operator is uninstalled (but only if the CSV has the plugin annotation).

If the user doesn't have authority to patch the operator config, we should warn them that the operator config can't be updated to remove the plugin.

cc pkreuser rhn-coreos-tunwu rhn-engineering-rhamilto