Integrate IoT Events (MQTT) with front-end to decrease event/alarm latency

[JimTharioAmazon]

Transition from polling the API Gateway endpoint periodically to listening for MQTT notifications on cloud resource state changes.

We can potentially have a optimal push notification starting from alarm state change, via SNS on the back-end, and then resent over MQTT for the browser application to react. We should be able to display a state change in <1 second with both of these mechanisms in place.

[JimTharioAmazon]

Let's consider starting with EventBridge or SNS topics for each major event type for MSAM for application-level event notification, such as:

1. Media (pipeline) Alert
2. CW Alarm state change
3. Any table record trigger via DynamoDB streams (add, update, delete). Need to limit noise from Content table.

Try to use an integration from SNS to IOT Events, so that our code only has to contend with publishing SNS messages.