implement Application Roles

[mipmip]

• [x] implement in experimental
• [ ] list of useful places
  • [x] content dashboard/menu
  • [x] toolbar -> tools
• [x] move to real location in menu
• [ ] available in preferences
• [ ] Documentation

[mipmip]

menu:
  - key: Developer
    title: "Developer"
    matchRole: siteDeveloper
    menuItems:
      - key: dashboard
      - key: etalage
      - key: readme