feat: Link API Gateway Methods to Integrations

[mildaniel]

Which issue(s) does this change fix?

N/A

Why is this change necessary?

To support sam local start-api for Terraform resources, we need to read in the Terraform API Gateway resources and convert them to their corresponding CFN resources.

How does it address the issue?

Adds support for linking API Gateway methods to their corresponding API Gateway integrations. Additional handling needed to be done for these resources since they don't map 1:1 between Terraform and CFN. In Terraform, integrations are their own resources whereas in CFN, they are a field under the AWS::ApiGateway::Method resource.

1. Added support for mapping internal integration resources to the corresponding REST API and Gateway Resource resources on the RestApiId and ResourceId fields, respectively.
2. Linked all internal integration resources to the Lambda functions they are proxied to on the Uri field of the integration.
3. Added additional handling during the translation to iterate over all methods, find the corresponding integration and map the fields from the integration to the ApiGatewayMethod.Properties.Integration field.

What side effects does this change have?

N/A

Mandatory Checklist

PRs will only be reviewed after checklist is complete

• Add input/output type hints to new functions/methods
• Write design document if needed (Do I need to write a design document?)
• Write/update unit tests
• Write/update integration tests
• Write/update functional tests if needed
• make pr passes
• make update-reproducible-reqs if dependencies were changed
• Write documentation

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[sriram-mv]

Overall looks good to me. Added one thing to be changed.

[moelasmar]

Thanks Daniel