Add allow_to_edit_own_delegation

[Elblinator]

See https://github.com/OpenSlides/OpenSlides/issues/6223 for context

Desired behaviour:

The settings need to be added in the settings > participants > vote delegation > a sub setting from Activate vote delegation

The group permission needs to be added in groups > participants: Under Can see participants. The title for the new permission should be Can edit own delegation. To edit your own delegation you need to permission to see participants (canSee should automatically be activated)

If a User can edit their own delegation then they should be able to open the edit dialog for themselves and be allowed to set and remove someone in „Voting right delegated to (proxy)“ and they should only be allowed to remove the user in „Voting right received from“ There should be an additional click path to open this dialog for yourself: participant-list > top right three dot menu > option to „Change your delegation“

[luisa-beerboom]

Backend done with OpenSlides/openslides-backend#2632

There is now a permission can_edit_own_delegation and a change to the user.update_self action