[ML] Improve styling for insufficient permissions message in Stack Management ML Jobs

[sophiec20]

Screenshots show behaviour in 7.9

Machine Learning jobs are listed in Kibana Stack Management.

If a user selects this link, they see a permissions denied message, if they do not have Machine Learning All Space privileges or do not have machine_learning_admin.

In cases where there is actually a permissions issue (i.e. ML feature is visible and user does not have ML All Space privileges or does not have machine_learning_admin), then please use the same style as seen in Users & Roles

Note: This Stack Management Machine Learning tab will eventually be used to allow admins to assign ML jobs to spaces, once the back end work is completed to support this functionality.

[elasticmachine]

Pinging @elastic/ml-ui (:ml)