This is a prep commit to separate the single test
'test_stream_send_message_events' into two separate tests named
'test_stream_send_message_events' & test_stream_update_message_events'
to verify the events related to send and update message, respectively.
As a part of introducing two new user settings
* 'automatically_follow_topics_policy'
* 'automatically_unmute_topics_policy'
in the next commit, we will extend 'test_stream_send_message_events'.
This logical separation helps in avoiding a single, super-long test.
db8229ae32