fix the logic for applicationset resources reconcilation when spec.applicationset.enabled is false

[ishitasequeira]

What type of PR is this?
/kind bug

What does this PR do / why we need it:
Currently when the ApplicationSet resources do not exist and we set spec.applicationset.enabled = false, the reconciliation fails giving us below error:

2023-11-29T07:15:04Z	ERROR	Reconciler error	{"controller": "argocd", "controllerGroup": "argoproj.io", "controllerKind": "ArgoCD", "ArgoCD": {"name":"argocd","namespace":"test"}, "namespace": "test", "name": "argocd", "reconcileID": "c83d8dba-9944-47c3-b8d1-9f75a60346e9", "error": "roles.rbac.authorization.k8s.io \"argocd-applicationset-controller\" not found"}
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).reconcileHandler
	/remote-source/deps/gomod/pkg/mod/sigs.k8s.io/controller-runtime@v0.16.3/pkg/internal/controller/controller.go:329
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).processNextWorkItem
	/remote-source/deps/gomod/pkg/mod/sigs.k8s.io/controller-runtime@v0.16.3/pkg/internal/controller/controller.go:266
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).Start.func2.2
	/remote-source/deps/gomod/pkg/mod/sigs.k8s.io/controller-runtime@v0.16.3/pkg/internal/controller/controller.go:227

Have you updated the necessary documentation?

• Documentation update is required by this PR.
• Documentation has been updated.

Which issue(s) this PR fixes:

Fixes https://issues.redhat.com/browse/GITOPS-3667

How to test changes / Special notes to the reviewer:

• Start the operator using make install run
• apply the below argocd configmap

apiVersion: argoproj.io/v1beta1
kind: ArgoCD
metadata:
  name: argocd
spec:
  controller:
    enabled: false
  redis:
    enabled: false
  repo:
    enabled: false
  server:
    enabled: false
  applicationSet:
    enabled: false

• No resources should be created for the argocd instance.

[anandf]

Instead of having a status of Unknown can we have a state called Disabled. It would be more intutive for the user to understand that the component is explicitly disabled.

[ishitasequeira]

We do not maintain a Disabled state today and add Unknown as the state for missing components like ApplicationSet if spec.applicationset = nil. It would be like adding a new behavior and a new Status as part of bugfix.

[anandf]

If not as part of this PR, we can create a separate PR for adding the Disabled state. That being a string and not part of the API spec, it can be introduced with minimal impact to end users.

[anandf]

• Could we set the component status to Disabled instead of Unknown.
• Could we add one more E2E scenario where we start from all components enabled, and disable each of them and another scenario for validating the HA scenario.
• 1-034_validate_applicationset_reconcile_enabled_set_false newly added test is failing. It is probably due to the ArgoCD instance added in the errors file.