Add Notification Support to Parse CloudBank for External Transfers

[ddrechse]

Create a new Service that manages Notifications for Parse Cloudbank

[ddrechse]

Have a service that supports subscribing and maintaining subscriptions for notifications on certain banking actions, in this case external transfers.

The service should allow a user to sign up for notifications upon a successful external transfer initially.

Upon a successful completion of an external transfer, a msg would be pushed to the new notification service. The service would look up whether the user wanted push notifications and, if so, would push a notification to the user via Parse push notification support https://docs.parseplatform.org/parse-server/guide/#push-notifications

The subscription service would allow users to subscribe to the different banking notifications supported and handle all CRUD aspects of user subscriptions

This feature will illustrate push notification support in Parse Server and also demonstrate the loosely coupled eventing mechanism common to microservices. Also demonstrate separation of concerns with one Parse service just being responsible for maintaining subscription data and pushing notifications to users.

DOD: Subscription service exists, handles all subscription CRUD operations, Supports reading subscription events from AQ and performs Push Notification. First subscription supported will be successful external transfers ( Transfers between 2 distinct banks)