MM-22706: pass along set_online flag in websocket response (#14591)

* MM-22706: pass along set_online flag in websocket response

To let the client know whether a user has created a post without
being online or not, we get the set_online query param and
pass it down to the websocket event being passed down to the client.

With this PR, the "data" field of the `posted` event will contain
a `set_online` boolean field set to true/false depending on the
query_param set_online value set in the createPost call.

* Setting to false for auto responder

Co-authored-by: mattermod <mattermod@users.noreply.github.com>

migrations/helper_test.go

@@ -206,7 +206,7 @@ func (me *TestHelper) CreatePost(channel *model.Channel) *model.Post {
 
 	utils.DisableDebugLogForTest()
 	var err *model.AppError
-	if post, err = me.App.CreatePost(post, channel, false); err != nil {
+	if post, err = me.App.CreatePost(post, channel, false, true); err != nil {
 		mlog.Error(err.Error())
 
 		time.Sleep(time.Second)