Support Applications in any namespace

[iandelahorne]

Describe the bug
With the introduction of Applications in any namespace, applications can now be deployed in namespaces outside of the ArgoCD operator's namespace (default argocd).

However, ArgoCD Image Updater does not support this yet, it only monitors the namespace it's deployed in. We are able to work around this by deploying ArgoCD Image Updater in each namespace we want to utilize it in. For example, if we have applications in the namespaces team1, team2, team3` that want to utilize the image updater, we deploy 3 instances - each with their own deployment, RBAC et c

To Reproduce

1. Deploy argocd image updater in the argocd namespace
2. Deploy an application in theargocd namespace with image update annotations
3. Deploy an application in the default namespace with image update annotations
4. The application in the default namespace is not updated, but the one in argocd is.

Expected behavior
The expected behavior is that the application in the default namespace is also updated. Ideally there should be a deployment mode similar to other ArgoCD components (such as Argo Rollouts) for deploying as a global controller, as well as a namespaced controller (which is the current behavior)

Version
0.12.2

[renchap]

Duplicate of #601?

[iandelahorne]

Looks to be, dunno how i missed it!