Add config option to disable access to cluster manager

[jeff-phillips-18]

Fixes:
Jira: https://issues.redhat.com/browse/RHODS-1945

The sandbox users will not have access to cluster management and therefore the link to Cluster manager console is useless.

Analysis / Root cause:
The dashboard only checks for the availability of the cluster manager it does not know if the user has access.

Solution Description:
Add a config setting to disable access to the cluster manager.

Example config map with disablement:

kind: ConfigMap
apiVersion: v1
metadata:
  name: odh-dashboard-config
  namespace: redhat-ods-applications
  uid: 3b8092d5-94b0-45d4-b010-1bd88e5968ff
  resourceVersion: '100273'
  creationTimestamp: '2021-09-24T12:37:29Z'
  managedFields:
    - manager: Mozilla
      operation: Update
      apiVersion: v1
      time: '2021-09-24T12:37:29Z'
      fieldsType: FieldsV1
      fieldsV1:
        'f:data':
          .: {}
          'f:disableClusterManager': {}
          'f:disableInfo': {}
          'f:disableSupport': {}
          'f:enablement': {}
data:
  disableClusterManager: 'true'
  disableInfo: 'false'
  disableSupport: 'false'
  enablement: 'true'

• The commits are squashed in a cohesive manner and have meaningful messages.
• For commits that came from upstream, [UPSTREAM] has been prepended to the commit message
• JIRA link(s): https://issues.redhat.com/browse/RHODS-1945
• The Jira story is acked
• An entry has been added to the latest build document in Build Announcements Folder.
• Testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious)

[cfchase]

LGTM

[cdcabrera]

looks like a couple of warnings on hook dependency for useMemo were thrown around the new ref

... = dashboardConfig.disableClusterManager ...