Integrate permission management in frontend for devices and platforms

Goal of this MR:

• implement permission management in devices and platforms
  • allow setting the visibility
  • allow selecting one or multiple permission groups
  • disallow access for entities that are private and where the user is not the owner
  • disallow to edit entities when user is not in the permission groups of the entity
  • validate visibility and permission groups
• add info which user created or updated the entity

Implements #211 (closed) and #212 (closed)