MGMT-20124: Introduce DependencyOnly property on Operator (#7525)

This property should be reserved for operator that can not be installed
as standalone operator.

This change is a prerequisite to be able to remove nvidia-gpu, amd-gpu or kmm operator if,
after choosing openshiftai, we found that no host has amd/nvidia gpu.

Author: pastequo

api/vendor/github.com/openshift/assisted-service/models/monitored_operator.go

@@ -4122,6 +4122,9 @@ definitions:
             package: github.com/lib/pq
           hints:
             noValidation: true
+      dependency_only:
+        type: boolean
+        description: Whether the operator can't be installed without being required by another operator.
 
   operator-monitor-report:
     type: object