MI-314: Migrate asset resolvers to constructs

[kai-nguyen-aligent]

Description of the proposed changes

• New package: nodejs-function-from-entry-construct — a CDK construct that creates a Node.js Lambda function from an entry file path. This construct automatically resolve TS file path to the bundled code.
• Enhanced step-function-from-file — baked in asset resolution and function injection support, allowing Step Function definitions to automatically resolve Lambda function references from file.

Notes to reviewers

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