[Chat Client] list_users does not check for formatting

[beelux]

As it currently stands, the formatting for the !who command output is well-defined in the GitBook:

Sadly, list_users/chat_007 does not check for it:

cn-lab-student/chat_client_check/check.py

Lines 123 to 138 in b02c6d3

	def list_users():
	client_name_1 = generate_name()
	client_name_2 = generate_name()
	client_name_3 = generate_name()
	client_process_1, _ = log_in(client_name_1)
	client_process_2, _ = log_in(client_name_2)
	client_process_3, output_buffer_3 = log_in(client_name_3)
	client_process_3.sendline('!who')
	clients_list = [[client_name_1, client_process_1], [client_name_2, client_process_2], [client_name_3, client_process_3]]
	[handle_pexpect(client_process_3, [process for _, process in clients_list], name, output_buffer_3, f'checking that the name {name} appears in !who output') for name, _ in clients_list]
	return client_process_3