Map phone number lookup results to their native rooms

When dialing a phone number, also look to see if there's a corresponding
native user for the resulting user, and if so, go to the native room
for that user.

src/dispatcher/actions.ts

@@ -100,6 +100,14 @@ export enum Action {
      */
     OpenDialPad = "open_dial_pad",
 
+    /**
+     * Dial the phone number in the payload
+     * payload: {
+     *     number: <phone number>,
+     * }
+     */
+    DialNumber = "dial_number",
+
     /**
      * Fired when CallHandler has checked for PSTN protocol support
      * payload: none