Support Geo Unified URL for Cloud Native Hybrid architectures

From gitlab-org/charts/gitlab#3522 (comment 1521830094):

gitlab-org/charts/gitlab#4532 (closed) was resolved with gitlab-org/charts/gitlab!3253 (merged).

The MR resolves the primary goal of this issue, though this issue's steps to reproduce use GET.

I think all that is remaining here is to make some changes to GET so that it can be used to deploy Geo with Unified URL.

@sranasinghe @nwestbury Should we close this issue, and open a new one in GET?

For example, this would help with gitlab#370312