Returns group information from an admin.
AdminId index of the admin.
Group number to retrieve, from 0 to N-1, where N is the value of GetAdminGroupCount(id).
Buffer to store the group's name. Note: This will safely chop UTF-8 strings.
Maximum size of the output name buffer.
A GroupId index and a name pointer, or INVALID_GROUP_ID and NULL if an error occurred.