Name: admin-list-request
Type: request
Purpose: >
  Get a list of participants appointed as admins
Response: admin-list
Inherits: message
Elements:
  Group-Id: { type: string, min_length: 3, max_length: 256 }
  Event-Id: { type: string, min_length: 3, max_length: 256 }
Notes: >
  Group-Id and Event-Id are mutually exclusive.
Rejection-Codes:
  22: Group and event ID must not be specified both
  41: Group does not exist
  42: Event does not exist