feat(invite): be able to call numbers from the invite dialog (#2555)

* feat(invite): be able to call numbers from the invite dialog

The major changes:
- Remove DialOutDialog, its views, redux hooks, css, and images.
  Its main functionality has been moved into AddPeopleDialog.
- Modify the AppPeopleDialog styling a bit so it is wider.
- Add phone numbers to AddPeopleDialog search results. Phone
  numbers are validated in parallel with the request for people
  and then appended to the result. The validation includes
  an ajax to validate the number is recognized as dialable by
  the server. The trigger for the validation is essentially if
  the entered input is numbers only.
- AddPeopleDialog holds onto the full object representation of
  an item selected in MultiSelectAutocomplete. This is so
  selected items can be removed on successful invite, leaving
  only unsuccessful items.
- More granular error handling on invite so individual invitees
  can be removed from the selected items list.

* squash: change load state, new regex for numbers

* squash: change strings, auto prepend 1 if no country code, add reminders

react/features/invite/functions.js

@@ -75,7 +75,7 @@ export function searchDirectory( // eslint-disable-line max-params
         jwt: string,
         text: string,
         queryTypes: Array<string> = [ 'conferenceRooms', 'user', 'room' ]
-): Promise<void> {
+): Promise<Array<Object>> {
     const queryTypesString = JSON.stringify(queryTypes);
 
     return new Promise((resolve, reject) => {
@@ -86,3 +86,31 @@ export function searchDirectory( // eslint-disable-line max-params
             .catch((jqxhr, textStatus, error) => reject(error));
     });
 }
+
+/**
+ * Sends an ajax request to check if the phone number can be called.
+ *
+ * @param {string} dialNumber - The dial number to check for validity.
+ * @param {string} dialOutAuthUrl - The endpoint to use for checking validity.
+ * @returns {Promise} - The promise created by the request.
+ */
+export function checkDialNumber(
+        dialNumber: string, dialOutAuthUrl: string): Promise<Object> {
+    if (!dialOutAuthUrl) {
+        // no auth url, let's say it is valid
+        const response = {
+            allow: true,
+            phone: dialNumber
+        };
+
+        return Promise.resolve(response);
+    }
+
+    const fullUrl = `${dialOutAuthUrl}?phone=${dialNumber}`;
+
+    return new Promise((resolve, reject) => {
+        $.getJSON(fullUrl)
+            .then(resolve)
+            .catch(reject);
+    });
+}