NIMQChatServerGetMembersParam 成员列表

成员的完整列表，这些成员属于 NIMQChatServerGetMembersParam,包括所有继承而来的类成员

cb	NIMQChatServerGetMembersParam
server_accid_list	NIMQChatServerGetMembersParam
server_accid_list_count	NIMQChatServerGetMembersParam
user_data	NIMQChatServerGetMembersParam