(gen2-migration) `generate` command should handle CloudFormation backed custom resources

### Is this feature request related to a new or existing Amplify category?

_No response_

### Is this related to another service?

_No response_

### Describe the feature you'd like to request

We need to support Gen1 custom resources that are created using direct CloudFormation templates.

See https://docs.amplify.aws/gen1/react/tools/cli/custom/cloudformation/

### Describe the solution you'd like

The solution should make use of the [CfnInclude](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.cloudformation_include.CfnInclude.html) construct.

https://github.com/aws-amplify/amplify-cli/pull/14410

### Describe alternatives you've considered

None

### Additional context

_No response_

### Is this something that you'd be interested in working on?

- [ ] 👋 I may be able to implement this feature request

### Would this feature include a breaking change?

- [ ] ⚠️ This feature might incur a breaking change