ArgoCD Sync Waves should be followed during app deletion

[whitleykeith]

Summary

When deleting an application, Argo should maintain sync waves during deletion at follow the reverse order for deletion.

i.e. I have a application that deploys manifest A at phase 0 and manifest B at phase 1. When deleting the application, it should delete B first and then A.

Motivation

When deploying applications that have an Operator + Custom Resource, we want the deletion to delete the Custom Resource, the operator, and then the CRD. Currently doing this can cause a hang on deletion since sometimes the operator will get deleted first.

Proposal

Sync waves should be following in reverse order during deletion, i.e. delete phase 3 -> phase 2 -> phase 1.

[raiviskrumins]

Having the same issue