Implement package directory flag

[nabuskey]

Per the pluggable packages proposal, I would like to introduce a new flag --package-dir. This specifies the directory that contain ArgoCD application yaml files.

When specified, it should:

1. Look for yaml files in the directory specified.
2. Parse and try to deserialize them into ArgoCD Applications.
3. If the repoURL fields use the file:// URI:

• Create a git repository custom resource..
• Update the repoURL field with the in-cluster url for the gitea repository.
• Apply updated manifest.

4. Otherwise apply directly the manifest.