settings: Add 'web_navigate_to_sent_message' setting.

In a2ef1d7e93, we made changes so
that when you send a message, your view jumps to the conversation
where you sent it.

For some users it was an improvement, few reported that it
disrupts their workflows.

This prep commit adds a setting which will be used to allow users
to decide whether to automatically go to conversation where they
sent a message.

web/src/server_events_dispatch.js

@@ -719,6 +719,7 @@ export function dispatch_normal_event(event) {
                 "send_stream_typing_notifications",
                 "send_private_typing_notifications",
                 "send_read_receipts",
+                "web_navigate_to_sent_message",
             ];
 
             const original_home_view = user_settings.web_home_view;