Remove the need for "interface" endpoints

[rdettai]

Currently, the Fuse needs 2 interface endpoints to be setup in order to access the Lambda and ECS APIs from within the VPC. This has a fixed cost of $0.01 per endpoint per hour.

The best solution to avoid this is probably to use a DynamoDB table to register API calls (DynamoDB can be accessed through a Gateway Endpoint, just like S3), then asynchronous functions outside the VPC would pick up the changes in the table and invoke the appropriate services.

Benefits:

• No more fixed costs
• This would also allow a more transactional management of the resources.

Drawbacks:

• Might add latency
• Adds complexity