Add AWS CloudWatch Alarm Event

**Is your feature request related to a problem? Please describe.**
I want to create a lambda for an AWS CloudWatch Alarm Event. I'm not able to find anything that seems to indicate there is already a struct that exists for the lambda handler to map the event automatically.

**Describe the solution you'd like**
I would like to have a struct created that allows the lambda handler event to map AWS CloudWatch Alarm events like the ones produced here: https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/AlarmThatSendsEmail.html#alarms-and-actions.

**Describe alternatives you've considered**
If there are alternative ways of doing this without me having to define my own struct for this, I'm open to using that instead.

**Additional context**
Add any other context or screenshots about the feature request here.