Describe the bug
A clear and concise description of what the bug is.

If you have the Control Plane in one namespace, argocd, and the agent in a different namespace, argocd-agent, when using destination mapping the application will not get copied over as the Agent will fail complaining it cannot create the Application in the argocd namespace.

Steps to reproduce the behaviour

1. Install the Control Plane and Agent in different namespaces using destination mapping
2. Create an application on the Control Plane
3. Note that it fails to get propagated over as the Agent tries to create the Application in the Control Name namespace rather then it's own.

Expected behavior
When the Application is being sourced from the Control Plane's namespace the Agent should be smart enough to change the namespace to it's own namespace.

Additional context
This is important because you need to install the Agent in a different namespace when you want to use Argo CD to manage the cluster the Control Plane resides on. Requiring the use of namespace mapping to handle this use case then precludes any oppty to share the Control Plane between cluster-config and multi-tenant apps use cases since users will often want to use Apps-In-Any-Namespace to support tenancy and not for mapping Applications.