see for context: OpenSlides/OpenSlides#6798

Wanted behavior
Login mask:

• below the internal login should be a button with "Login as guest" as text
• If this button is pressed the anonymous user should be:
  • If only one meeting is public -> should be navigated to the public meeting
  • If more than one meeting is public -> should be navigated to the dashboard, where every public meeting is display

General:

• If you are using OpenSlides as a anonymous... In the top right corner
  • The icon next to your name should be "no_accounts"
  • The displayed name should be "Anonymous"
  • the "My profile"-Option should be hidden
  • The "Logout" button should have the icon "Login", and if pressed you should be navigated to the login page "..../login"

Orga-level as an anonymous user:

• Only "Dashboard" should be visible
• In the dashboard every meeting which is public should be displayed

Meeting:

• Settings:
  • There will be a new setting after Locked from inside (Close meetings from inside #3869) is merged
  • This (this issue) new setting to allow anonymous users should be below locked_from_inside
    • it should be a checkbox
    • the label (for now) should be "Allow anonymous users"
    • There should be a hint below this setting, the hint should be as follows:
      • If the anonymous group has no permissions at all: "The anonymous group will become visible at the url: '##/participants/groups', please configure what your anonymous users are allowed to see"
      • If the anonymous group has one or more permissions: "The anonymous group is at url: '##/participants/groups'. Your anonymous group is already allowed to see some of your contents, please configure the permissions according to your liking"
  • Locked_from_inside and make a meeting public should NOT be allowed to be true at the same time
    • a locked meeting from the inside is not allowed to be public
    • a public meeting is not allowed to be locked from the inside
    • If one checkbox is activated and the other is empty the empty one should be disabled, if both are (somehow) activated at the same time neither should be disabled
• Group-Matrix with the new anonymous group:
  • The group should only be visible if the setting "Allow anonymous users" is activated
  • Guest-group is only allowed to have reading-permissions, every writing permission should be off and disabled

Additional context

• we also have the new setting to lock a single participant out (Lock participant out of meeting #3815). That setting can be active while a meeting is public --> these two settings are independent from each other