Add AWS::Serverless::Connector support to the AWS Serverless Application Repository

[sopel]

Description

Despite its name suggesting otherwise, the AWS::Serverless::Connector is not yet contained within the (at times surprisingly limited) List of Supported AWS Resources for the AWS Serverless Application Repository.

• I'm filing this a DX bug, because SAR should really cover all AWS::Serverless::* resource types and properties at launch (or shortly thereafter) to avoid future users wasting hours to convert their apps to the fancy and widely advertised new AWS::Serverless::Connector, only to ultimately hit this blocker that requires rolling back all those changes 😉

Steps to reproduce

1. Create a new SAM app with sam init.
2. Replace the code with an example from AWS::Serverless::Connector, e.g. "have an Amazon SNS topic write to a Lambda function, which then writes to an Amazon DynamoDB table"
3. Add minimal AWS::ServerlessRepo::Application metadata
4. Use sam validate --lint and observe it succeeds
5. Use sam publish to push the SAM app to the Serverless Application Repository and observe it fails.

Observed result

Using sam publish fails with the following error message:

❯ sam publish
Publish Failed
Error: The template contains unsupported resource types. [AWS::Serverless::Connector]
Please follow the instructions in https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-template-publishing-applications.html

Expected result

Using sam publish succeeds and makes the SAM app available in the Serverless Application Repository.

Additional environment details

1. OS: N/A
2. If using the SAM CLI, sam --version: SAM CLI, version 1.74.0
3. AWS region: eu-west-1