Allow reporting status from Manifest function of AgentAddon

[ctron]

When the agent reconciles the target's state in the Manifest function, it might encounter an error, which at this moment doesn't allow it reconcile.

However, there seems to be no proper way to record this, other than returning an error, which will re-trigger the reconciliation.

I think it would be helpful if the agent could contribute to the conditions of the ManagedClusterAddOn resource.

[qiujian16]

/kind enhancement

[openshift-ci]

@qiujian16: The label(s) kind/enhancement cannot be applied, because the repository doesn't have them.

In response to this:

/kind enhancement

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[qiujian16]

hrm, I think it makes sense. we need to think also whether directly return error make sense since it triggers reconcile and it is highly possible to return error again.

[ctron]

Maybe there can be two kinds of errors: temporary error (which re-trieggers) and permanent error (which does not)