AppSync API Cache

This template creates an ApiCache for a GraphQL API. The `ApiCache` resource is of type `AWS::AppSync::ApiCache` and has properties such as `Type` which is set to `SMALL`, `ApiCachingBehavior` which is set to `FULL_REQUEST_CACHING`, `Ttl` which is set to 1200, `TransitEncryptionEnabled` which is set to true, and `AtRestEncryptionEnabled` which is set to true.