Change user.scope for Meeting admins if they are admins in several meetings

[Elblinator]

Current behaviour:
If a user (Ann) is a meeting admin (more precise when Ann is allowed to manage participants) in two meetings and another user (Ben) is only in these two meetings then Ann is currently not allowed to change the personal information from Ben with the backend reply:

Error: You are not allowed to perform action user.update. Missing permissions: OrganizationManagementLevel can_manage_users in organization # or CommitteeManagementLevel can_manage in committee #

Wanted behaviour:
As long as Ann is allowed to manage participants in every meeting Ben is a participant in then Ann is allowed to change Ben's personal information