feat: Group Members Management

Created by: ogerly

Pull Request

• member list of a group is displayed
• member role can be changed

Issues

• fixes #5344 (closed)

Todo

• test new pages and components
• remove my setting My Groups? from settings page
• remove a member?
  • implement later, see issue #5389 (closed)
• change group type?
  • implement later, see issue #5387
• translate:
  • select options groupType
  • select options group.actionRadius
• remove locale:
  • group.unfollowing?
  • group.visibility
  • group.showMyCreatedGroups?
  • group.showAllMyGroups?
  • group.back
• followup issue #5397 (closed)
  • may have a look it if something should be already in here …
• cleanup: search for Wolle