Refactor typescript message handler

This makes it so that, to register a handler on a given topic, you just
need to call a single function, rather than assembling the entire
flatbuffer request message by yourself.

Change-Id: I540f475d9650ab27efe715a05d7586719045aeed
diff --git a/y2020/www/camera_main.ts b/y2020/www/camera_main.ts
index 8c7ae55..58e5bed 100644
--- a/y2020/www/camera_main.ts
+++ b/y2020/www/camera_main.ts
@@ -1,9 +1,11 @@
 import {Connection} from 'org_frc971/aos/network/www/proxy';
 
 import {ImageHandler} from './image_handler';
+import {ConfigHandler} from 'org_frc971/aos/network/www/config_handler';
 
 const conn = new Connection();
 
 conn.connect();
 
 const iHandler = new ImageHandler(conn);
+const configHandler = new ConfigHandler(conn);