Application Group focus as opposed to namespace/cluster focus for gitops files

[mpatters72]

• We often have engineering teams who own groups of applications as opposed to fully dedicated namespaces and clusters per team.

• It is challenging to maintain CODEOWNERS files for every single gitops file in the current cloud/namespace/cluster format. Being able to use CODEOWNERS this way can set the appropriate teams to approve merging gitops PRs

• Adding an optional cloud\**app_grp**\namespace\cluster would allow CODEOWNERs to be set at a lower level.

• My team uses ArgoCD ApplicationSet to apply gitops manifests. We like to manage groups of ArgoCD applications to be created and updated every time they are added to a new cluster. If we were able to add optional app_grp we could automatically create new ArgoCD applications by using ApplicationSet Git Directory Generator