Add cryostat origin to APIServer CORS allowed origins

[jan-law]

In order for the frontend to access the OAuth server logout endpoint, the APIServer needs the cryostat web host added to the spec additionalCORSAllowedOrigins. The docs mention this "may be needed to access the API and the integrated OAuth server from JavaScript applications". If I don't include this spec, the /logout request fails with a CORS error.
Here's a hardcoded example:

apiVersion: config.openshift.io/v1
kind: APIServer
metadata:
  ...
spec:
  additionalCORSAllowedOrigins:
  - cryostat-sample-default\.apps\.jalaw0\.lab\.upshift\.rdu2\.redhat\.com

Originally posted by @jan-law in https://github.com/cryostatio/cryostat/pull/786#discussion_r773471630