Add ACL support to dashboard tabs

Dashboard tabs could be seen by other users than admin with fd#5734 so plugins adding tab to dashboard should make sure ACLs are respected and no info is shown that the user is not allowed to see.

Actual behavior

All data is displayed

Expected behavior

Only allowed data should be displayed

Step by step description of new behaviour

1. Go to dashboard systems or network tab
2. You should only see systems and information you are allowed to see

Benefits

Give dashboard access to managers

Possible Drawbacks

Computing stats might be a bit slower