Summary:
Ref T4324. Currently, notifications data is `POST`ed to the Aphlict server in the `application/x-www-form-urlencoded` format. This works fine for simple data but is problematic for nested data. For example:
```lang=php
array(
'data' => array(
'key' => '6021329908492455737',
'type' => 'PhabricatorNotificationAdHocFeedStory',
),
'subscribers' => array(
'PHID-USER-y7ofqm276ejs62yqghge',
),
);
```
Is encoded as `data%5Bkey%5D=6021329908492455737&data%5Btype%5D=PhabricatorNotificationAdHocFeedStory&subscribers%5B0%5D=PHID-USER-y7ofqm276ejs62yqghge`. This string is then (incorrectly) decoded by `querystring.parse` as:
```lang=javascript
> querystring.parse('data%5Bkey%5D=6021329908492455737&data%5Btype%5D=PhabricatorNotificationAdHocFeedStory&subscribers%5B0%5D=PHID-USER-y7ofqm276ejs62yqghge');
{ 'data[key]': '6021329908492455737',
'data[type]': 'PhabricatorNotificationAdHocFeedStory',
'subscribers[0]': 'PHID-USER-y7ofqm276ejs62yqghge' }
```
Test Plan: Sent test notifications from `/notification/status/` and verified that the notifications still worked.
Reviewers: #blessed_reviewers, epriestley
Reviewed By: #blessed_reviewers, epriestley
Subscribers: epriestley, Korvin
Maniphest Tasks: T4324
Differential Revision: https://secure.phabricator.com/D9386