Issue #, if available:
N/A

Description of changes:

This PR adds an optional 'reason' field to the CloudFormation Custom Resource response model. This enhancement allows users to provide detailed failure reasons for Custom Resource creation/update operations, particularly useful in scenarios where the Lambda function is hosted in a separate account and logs are not directly accessible. The 'reason' field enables better error reporting and debugging for consumers of the Custom Resource.

Checklist

• Meet tenets criteria
• Update tests
• Update docs
• PR title follows conventional commit semantics

Breaking change checklist

RFC issue #: N/A

• Migration process documented
• Implement warnings (if it can live side by side)

Changes made:

• Added an optional 'reason' field to the Response class for CloudFormation Custom Resources
• Updated CloudFormationResponse to include the 'reason' in the response JSON when provided
• Modified the Response builder to allow setting a custom reason
• Ensured backward compatibility by making the 'reason' field optional
• Added new test cases to verify the behavior of the new 'reason' field
• Updated existing tests to include checks for the 'reason' field
• Added appropriate JavaDoc comments for the new 'reason' field and its usage

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