Operator doesn't remove applicationset controller when disabled

The Operator doesn't remove resources for applicationset controller when the user disables the feature.

To enable the feature, the user has to specify at least an empty applicationSet block, i.e.

spec:
  applicationSet: {}

The Operator will create the appropriate resources (e.g. Deployment, Roles, etc).

However, when the user removes above applicationSet block, the Operator does not delete the resources it created, thus not disabling the applicationset feature and leaving unwanted resources on the cluster.

To reproduce:

• Enable applicationset in the Operand by adding .spec.applicationSet
• Watch for resources being created
• Disable applicationset in the Operand by removing .spec.applicationSet
• Observe resources persisting