MM-35297 Add the ability to control if thread is followed when marking post as unread and don't autofollow from API (#17799)

* Add the ability to control if thread is followed when marking post as unread and don't autofollow from API

* Fix style

app/post_test.go

@@ -2078,7 +2078,7 @@ func TestCollapsedThreadFetch(t *testing.T) {
 		thread, nErr := th.App.Srv().Store.Thread().Get(postRoot.Id)
 		require.NoError(t, nErr)
 		require.Len(t, thread.Participants, 1)
-		th.App.MarkChannelAsUnreadFromPost(postRoot.Id, user1.Id, true)
+		th.App.MarkChannelAsUnreadFromPost(postRoot.Id, user1.Id, true, true)
 		l, err := th.App.GetPostsForChannelAroundLastUnread(channel.Id, user1.Id, 10, 10, true, true, false)
 		require.Nil(t, err)
 		require.Len(t, l.Order, 1)