Convert ext lib to typescript

ext/src/lib/messageRouter.ts

@@ -0,0 +1,26 @@
+"use strict";
+
+type SenderCallback = (message: any, details: any) => void;
+
+const routeMap = new Map<string, SenderCallback>();
+
+function register (routeName: string, senderCallback: SenderCallback) {
+    routeMap.set(routeName, senderCallback);
+}
+
+function deregister (routeName: string) {
+    routeMap.delete(routeName);
+}
+
+function handleMessage (message: any, details?: any) {
+    const destination = message.subject.split(":")[0];
+    if (routeMap.has(destination)) {
+        routeMap.get(destination)(message, details);
+    }
+}
+
+export default {
+    register
+  , deregister
+  , handleMessage
+};