[Controller] Address Webservice generator pattern with multiple Ingresses referencing the same host

Summary

The Webservice chart supports the generator pattern, meaning that you can spawn multiple instances of Webservice resources (Deployments, Ingresses, etc.).

During https://gitlab.com/gitlab-org/gl-openshift/gitlab-operator/-/merge_requests/134, we found that multiple Ingress resources that reference the same host is not supported (at least by default - we haven't yet found any documentation or source for this error All hosts are taken by other resources, so at the moment we assume it's coming from an admission controller somewhere in OpenShift). Worth noting that we haven't seen this error in non-OpenShift environments, so it could be specific to that platform.

We expect this will cause the GitLab Operator to return an error when we start respecting the generator pattern from the Charts in the GitLab Operator, as we'd be deploying multiple Ingresses that refer to the same host (with different paths).

We'll need to test this and find an appropriate solution. One idea that came to mind when brainstorming was to combine the paths from each Ingress resource into a single Ingress resource. @WarheadsSE mentioned a potential downside of this approach is that certain functionality, such as proxying, can only be done at the Ingress level and not per-path.