Teams dashboard widget

[juliusknorr]

• Should list all teams (circles) a user is part of
  • Clicking navigates to the team overview in contacts
• Should offer a button to navigate to the team management within contacts
• We can use the existing circles API as a start and later API for teams server#43683

Out of scope for now

• Should allow to expand a team to list all items that are shared with this specific team