Role based access control

[germanosin]

Implemented. Documentation is here / @Haarolean

The main idea of this feature is to provide access control for authenticated users based on roles.
Backend should support reading role bindings from git, s3, http, local yaml config
like

roleBindings:
   roleName:
     users: 
       - userName

and role access control file, like

roles:
    roleName:
    permissions:
          - resource: consumerGroups
            includes: ["/.*/"]
            excludes: []
            allowedActions: ["listTopics"]

List of resources and actions should be defined and described in separate document.
Using this bindings and ACL lists, backend should check all actions from authenticated users and provide this list to frontend.
Frontend should use this data to show/hide certain action buttons, menus

[Haarolean]

Related: #482 #1027 #1352