Add operation_mode to KPOps config

[raminqaf]

The user should be able to determine KPOps's "mode".
KPOps should run in two modes:

1. Argo: The commands (deploy, destroy, reset, and clean) will only manifest Kubernetes resources. See Manifest Kubernetes resources for each KPOps command #536
2. Manifest: only manifest the Helm charts
3. Default: How so far KPOps is handling the pipeline components

This can be passed the commands as an option --operation-mode or be configured through the config.yaml file

[raminqaf]

Closed with #541